Publications by authors named "Lequan Liu"

26 Publications

  • Page 1 of 1

Zr-Al co-doped SrTiO with suppressed charge recombination for efficient photocatalytic overall water splitting.

Chem Commun (Camb) 2021 Oct 12;57(81):10640-10643. Epub 2021 Oct 12.

TJU-NIMS International Collaboration Laboratory, Key Lab of Advanced Ceramics and Machining Technology (Ministry of Education) and Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, P. R. China.

Zr-Al co-doped SrTiO with reduced Ti concentration demonstrates more than 2 times enhancement compared with Al-doped SrTiO in photocatalytic overall water splitting. Systematic studies reveal that the co-doping of Zr can reduce the substitution of Ti by Al and effectively suppress the formation of charge carrier recombination centers (Ti).
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http://dx.doi.org/10.1039/d1cc04514hDOI Listing
October 2021

Hydrated electrons mediated in-situ construction of cubic phase CdS/Cd thin layer on a millimeter-scale support for photocatalytic hydrogen evolution.

J Colloid Interface Sci 2021 Sep 8;607(Pt 1):769-781. Epub 2021 Sep 8.

TJU-NIMS International Collaboration Laboratory, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, People's Republic of China; International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.

In this study, non-noble metal Cd decorated cubic phase CdS (CdS/Cd) thin layer on a millimeter-scale chitosan-Mg(OH) xerogel beads (CMB) were elaborately designed and successfully synthesized via facile hydrated electrons (e) assistant strategy. The in-situ formation of metallic Cd was driven by e generated from UV/NaSO process. Owing to metallic Cd, [email protected]/Cd exhibited better visible-light absorption ability and more efficient separation capability for photo-induced carriers, its hydrogen production efficiency was about threefold improved compared to [email protected] Both characterization methods and density functional theory calculations determined a built-in electric field from metallic Cd to CdS and Ohmic-contact between Cd and CdS, which largely promoted the carriers transfer efficiency. Moreover, the introduction of metallic Cd on the CdS could reduce the ΔG, thus greatly boosting the photocatalytic hydrogen production efficiency. This work provides a simple and green approach to construct metallic Cd coupled semiconductor to achieve efficient photocatalytic applications.
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http://dx.doi.org/10.1016/j.jcis.2021.09.039DOI Listing
September 2021

Insights into the Operation of Noble-Metal-Free Cocatalyst 1T-WS -Decorated Zn Cd S for Enhanced Photocatalytic Hydrogen Evolution.

ChemSusChem 2021 Aug 18. Epub 2021 Aug 18.

TJU-NIMS International Collaboration Laboratory, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin, 300072, P. R. China.

Due to inefficient charge separation and low surface catalytic conversion efficiencies, cocatalysts are required for achieving photocatalytic hydrogen evolution. Being a noble-metal-free cocatalyst, metallic 1T-WS with excellent conductivity can function for this reaction. Herein, 1T-WS /Zn Cd S is constructed via a simple and feasible grinding approach. The composite containing 7.5 % 1T-WS in 1T-WS /Zn Cd S achieves a hydrogen evolution rate of 61.65 mmol g  h and an external quantum efficiency of 8.04 % at 420 nm, which is 37 times that of bare Zn Cd S (1.67 mmol g  h ). The electrical conductivity of metallic 1T-WS reduces the transfer impedance at the interface and thus accelerates the non-radiative energy transfer and electron transport rate. The different Fermi levels of 1T-WS and Zn Cd S form a Schottky junction, which promotes the transfer of photogenerated electrons from Zn Cd S to 1T-WS . More importantly, the close interface contact between 1T-WS and Zn Cd S results in strong electron interactions, which is conducive to the spatial separation of photogenerated electrons and holes. This work will further expand the application of 1T-WS in the photocatalytic hydrogen evolution process.
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http://dx.doi.org/10.1002/cssc.202101670DOI Listing
August 2021

Boron Dopant Induced Electron-Rich Bismuth for Electrochemical CO Reduction with High Solar Energy Conversion Efficiency.

Small 2021 Jul 16;17(29):e2101128. Epub 2021 Jun 16.

TJU-NIMS International Collaboration Laboratory, Key Lab of Advanced Ceramics and Machining Technology (Ministry of Education) and Tianjin Key Laboratory of Composite and Functional Materials, School of Material Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China.

Electrochemical CO reduction to formate offers a mild and feasible pathway for the utilization of CO , and bismuth is a promising metal for its unique hydrogen evolution reaction inhibition. Reported works of Bi-based electrodes generally exhibit high selectivity while suffering from relatively narrow working potential range. From the perspective of electronic modification engineering, B-doped Bi is prepared by a facile chemical reduction method in this work. With B dopant, above 90% Faradaic efficiency for formate over a broad window of working potential of -0.6 to -1.2 V (vs. reversible hydrogen electrode) is achieved. In situ Raman spectroscopy, X-ray adsorption spectroscopy, and computational analysis demonstrate that the B dopant induces the formation of electron-rich bismuth, which is in favor of the formation of formate by fine-tuning the adsorption energy of *OCHO. Moreover, full-cell electrolysis system coupled with photovoltaic device is constructed and achieves the solar-to-formate conversion efficiency as high as 11.8%.
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http://dx.doi.org/10.1002/smll.202101128DOI Listing
July 2021

Designing Carbonized Loofah Sponge Architectures with Plasmonic Cu Nanoparticles Encapsulated in Graphitic Layers for Highly Efficient Solar Vapor Generation.

Nano Lett 2021 Feb 15;21(4):1709-1715. Epub 2021 Feb 15.

TJU-NIMS International Collaboration Laboratory, Key Lab of advanced Ceramics and Machining Technology (Ministry of Education), Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, P. R. China.

Solar vapor generation represents a promising approach to alleviate water shortage for producing fresh water from undrinkable water resources. Although Cu-based plasmonics have attracted tremendous interest due to efficient light-to-heat conversion, their application faces great challenges in the oxidation resistance of Cu and low evaporation rate. Herein, a hybrid of three-dimensional carbonized loofah sponges and graphene layers encapsulated Cu nanoparticles is successfully synthesized via a facile pyrolysis method. In addition to effective light harvesting, the localized heating effect of stabilized Cu nanoparticles remarkably elevated the surface temperature of [email protected]/CLS to 72 °C, and a vapor generation rate as high as 1.54 kg m h with solar thermal efficiency reaching 90.2% under 1 Sun illumination was achieved. A study in the purification of sewage and muddy water with [email protected]/CLS demonstrates a promising perspective in a practical application. These results may offer a new inspiration for the design of efficient nonprecious Cu-based photothermal materials.
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http://dx.doi.org/10.1021/acs.nanolett.0c04511DOI Listing
February 2021

Efficient photocatalytic conversion of CH into ethanol with O over nitrogen vacancy-rich carbon nitride at room temperature.

Chem Commun (Camb) 2021 Jan;57(7):871-874

TJU-NIMS International Collaboration Laboratory, Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education) and Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China. and Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin 300072, China and International Centre for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Japan.

A record ethanol production rate of 281.6 μmol g-1 h-1 for the photocatalytic conversion of methane over nitrogen vacancy-rich carbon nitride at room temperature was achieved. Systematic studies demonstrate that the CH4 was activated by the highly reactive ˙OH radicals generated, via H2O2, from the photo-reduction of O2 with H2O.
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http://dx.doi.org/10.1039/d0cc07397kDOI Listing
January 2021

Cl modification for effective promotion of photoelectrochemical water oxidation over BiVO.

Chem Commun (Camb) 2020 Nov 5;56(86):13153-13156. Epub 2020 Oct 5.

TJU-NIMS International Collaboration Laboratory, Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education) and Tianjin Key Laboratory of Composite and Functional Materials, School of Material Science and Engineering, Tianjin University, Tianjin 300072, China.

Postsynthetic treatment is an attractive method to enhance photoelectrochemical water splitting. The facile Cl modification approach developed in this work remarkably promotes the photocurrent density of BiVO up to 2.7 mA cm by facilitating carrier transfer in addition to a charge carrier separation efficiency enhancement.
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http://dx.doi.org/10.1039/d0cc05334aDOI Listing
November 2020

Copper nanoparticles selectively encapsulated in an ultrathin carbon cage loaded on SrTiO as stable photocatalysts for visible-light H evolution via water splitting.

Chem Commun (Camb) 2019 Oct;55(86):12900-12903

TJU-NIMS International Collaboration Laboratory, Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education) and Tianjin Key Laboratory of Composite and Functional Materials, School of Material Science and Engineering, Tianjin University, Tianjin 300072, China. and Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin 300072, China and International Centre for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Japan.

One-nanometre-thick carbon cage encapsulated copper nanopaticles on SrTiO3 (STO) synthesized through a facile chemical vapour deposition method showed remarkable stability and performance for both photocatalytic hydrogen evolution and thermocatalytic reduction of 4-nitrophenol. X-ray photoelectron spectroscopy and Raman results demonstrate that the graphene cage effectively protected Cu nanoparticles from being oxidized.
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http://dx.doi.org/10.1039/c9cc05228cDOI Listing
October 2019

Remarkable Visible-Light Photocatalytic Activity Enhancement over Au/p-type TiO Promoted by Efficient Interfacial Charge Transfer.

ACS Appl Mater Interfaces 2019 Jul 26;11(27):24154-24163. Epub 2019 Jun 26.

TJU-NIMS International Collaboration Laboratory, Key Lab of Advanced Ceramics and Machining Technology (Ministry of Education) and Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering , Tianjin University , Tianjin 300072 , China.

Metal-induced photocatalysis has emerged as a promising approach for exploiting visible-light-responsive composite materials for solar energy conversion, which is generally hindered by low photocatalytic efficiency. Herein, for the first time, an Au/p-TiO (p-type TiO) strategy with the hole transfer mechanism is developed, remarkably promoting visible-light photocatalytic performance. An efficient acetone evolution rate (138 μmol·g·h) in the photocatalytic isopropyl alcohol (IPA) degradation under λ = 500 nm light (light intensity, 5.5 mW/cm) was achieved over Au/p-TiO, which is approximately 5 times as high as that over Au/n-TiO under the same conditions. Photoluminescence and electrochemical impedance spectroscopy measurements indicate enhanced charge carrier separation and transfer for Au/p-TiO. In an elaborate study, apparent quantum efficiency and transmission electron microscopy characterization on selective PbO deposition over p-TiO revealed that visible-light-excited holes other than electrons generated in the Au interband transition transferred to p-TiO, which is opposite to the general route in Au/n-TiO (n-type TiO). Energetic holes generated in the d band of Au led to a fluent transfer across the Schottky barrier, which is further confirmed by the IPA photodegradation mechanism study with different scavengers over Au/p-TiO. This discovery opens up new opportunities in designing and developing efficient metal semiconductor composite materials with visible-light response.
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http://dx.doi.org/10.1021/acsami.9b07110DOI Listing
July 2019

CO tolerance of Pt/FeO catalyst in both thermal catalytic H oxidation and electrochemical CO oxidation: the effect of Pt deficit electron state.

Phys Chem Chem Phys 2016 Oct;18(42):29607-29615

TU-NIMS Joint Research Center, Key Lab of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin, China. and International Center for Materials Nanoarchitectonics (WPI-MANA), Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan. and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China.

CO poisoning of Pt catalysts is one of the major challenges to the commercialization of proton exchange membrane fuel cells. One promising solution is to develop CO-tolerant Pt-based catalysts. A facilely synthesized Pt/FeO catalyst exhibited outstanding CO tolerance in the oxidation of H and electrochemical CO stripping. Light-off temperature of HO formation over Pt/FeO was achieved even below 30 °C in the presence of 3000 ppm CO at a space velocity of 18 000 mL g h. For the electrochemical oxidation of CO, the onset and peak potentials decreased by 0.17 V and 0.10 V, respectively, in comparison with those of commercial Pt/C. More importantly, by a combination of hard X-ray photoemission spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies it was found that the decreased electron density of Pt in Pt/FeO enhanced the mobility of adsorbed CO, suppressed Pt-CO bonding and significantly increased the CO tolerance of Pt/FeO.
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http://dx.doi.org/10.1039/c6cp05289dDOI Listing
October 2016

Nanometals for Solar-to-Chemical Energy Conversion: From Semiconductor-Based Photocatalysis to Plasmon-Mediated Photocatalysis and Photo-Thermocatalysis.

Adv Mater 2016 Aug 17;28(32):6781-803. Epub 2016 May 17.

TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China.

Nanometal materials play very important roles in solar-to-chemical energy conversion due to their unique catalytic and optical characteristics. They have found wide applications from semiconductor photocatalysis to rapidly growing surface plasmon-mediated heterogeneous catalysis. The recent research achievements of nanometals are reviewed here, with regard to applications in semiconductor photocatalysis, plasmonic photocatalysis, and plasmonic photo-thermocatalysis. As the first important topic discussed here, the latest progress in the design of nanometal cocatalysts and their applications in semiconductor photocatalysis are introduced. Then, plasmonic photocatalysis and plasmonic photo-thermocatalysis are discussed. A better understanding of electron-driven and temperature-driven catalytic behaviors over plasmonic nanometals is helpful to bridge the present gap between the communities of photocatalysis and conventional catalysis controlled by temperature. The objective here is to provide instructive information on how to take the advantages of the unique functions of nanometals in different types of catalytic processes to improve the efficiency of solar-energy utilization for more practical artificial photosynthesis.
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http://dx.doi.org/10.1002/adma.201600305DOI Listing
August 2016

High performance Au-Cu alloy for enhanced visible-light water splitting driven by coinage metals.

Chem Commun (Camb) 2016 Mar;52(25):4694-7

TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, P. R. China. and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, P. R. China and Tianjin Key Laboratory of Composite and Functional Materials and Key Lab of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin 300072, P. R. China and International Center for Materials Nanoarchitectonics (WPI-MANA) and Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), Japan.

A Au-Cu alloy strategy is, for the first time, demonstrated to be effective in enhancing visible-light photocatalytic H2 evolution via promoting metal interband transitions. Au3Cu/SrTiO3, in which oxidation of Cu was successfully restrained, showed the highest visible-light H2 evolution activity.
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http://dx.doi.org/10.1039/c6cc00717aDOI Listing
March 2016

Highly efficient and stable photocatalytic reduction of CO2 to CH4 over Ru loaded NaTaO3.

Chem Commun (Camb) 2015 May;51(36):7645-8

Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan.

An efficient and stable photocatalytic activity was obtained over NaTaO3 by introducing an electron donor (H2) into the CO2 reduction process with water. Ru/NaTaO3 demonstrated the best activity (CH4 51.8 μmol h(-1) g(-1)) and product selectivity in converting CO2 to CH4.
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http://dx.doi.org/10.1039/c5cc01124hDOI Listing
May 2015

A highly durable p-LaFeO3/n-Fe2O3 photocell for effective water splitting under visible light.

Chem Commun (Camb) 2015 Feb;51(17):3630-3

Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, 060-0814, Japan.

A new p-type photocathode LaFeO3 was successfully fabricated, and a stable (120 h) and effective water splitting (H2: 11.5 μmol h(-1), O2: 5.7 μmol h(-1)) was realized via construction of a p-LaFeO3/n-Fe2O3 photocell. This study offers a new alternative to p-type photocathode materials and the low cost design of durable PEC devices for solar conversion.
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http://dx.doi.org/10.1039/c4cc09240fDOI Listing
February 2015

Constructing a multicomponent junction for improved visible-light photocatalytic performance induced by Au nanoparticles.

Chem Commun (Camb) 2015 Feb;51(11):2173-6

TU-NIMS Joint Research Center and Tianjin Key Laboratory of Composite and Functional Materials, School of Material Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin, P. R. China.

Au induced visible-light photocatalytic performance is, for the first time, demonstrated to be effectively enhanced by a proper construction of a junction nanostructure. A study of the ˙O2(-) and H2O2 radicals indicates the efficient electron transfer across the Au-SrTiO3-TiO2 composite facilitated by the junction effect is responsible for the enhancement, and ultimately promotes the photocatalytic process.
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http://dx.doi.org/10.1039/c4cc08556fDOI Listing
February 2015

Photocatalytic reduction of carbon dioxide by hydrous hydrazine over Au-Cu alloy nanoparticles supported on SrTiO3/TiO2 coaxial nanotube arrays.

Angew Chem Int Ed Engl 2015 Jan 24;54(3):841-5. Epub 2014 Nov 24.

International Center for Materials Nanoarchitectonics (MANA), and Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan).

Efficient photocatalytic conversion of CO2 into CO and hydrocarbons by hydrous hydrazine (N2H4⋅H2O) is achieved on SrTiO3/TiO2 coaxial nanotube arrays loaded with Au-Cu bimetallic alloy nanoparticles. The synergetic catalytic effect by the Au-Cu alloy nanoparticles and the fast electron-transfer in SrTiO3/TiO2 coaxial nanoarchitecture are the main reasons for the efficiency, while N2H4⋅H2O as the H source and electron donor provides a reducing atmosphere to protect the surface Cu atoms from oxidation, therefore maintaining the alloying effect which is the basis for the high photocatalytic activity and stability. This approach opens a feasible route to enhance the photocatalytic efficiency, which also benefits the development of photocatalysts and co-catalysts.
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http://dx.doi.org/10.1002/anie.201409183DOI Listing
January 2015

Bifunctional-nanotemplate assisted synthesis of nanoporous SrTiO₃ photocatalysts toward efficient degradation of organic pollutant.

ACS Appl Mater Interfaces 2014 Dec 2;6(24):22726-32. Epub 2014 Dec 2.

TU-NIMS Joint Research Center and Tianjin Key Laboratory of Composite and Functional Materials, School of Material Science and Engineering, Tianjin University , Tianjin 300072, People's Republic of China.

Nanoporous SrTiO3 photocatalysts were fabricated via a novel technique, the nanotemplate assisted sol-gel hydrothermal reaction. In the alkaline-environment hydrothermal reaction, the SiO2 nanotemplate not only served as pore generator but also worked on adjusting the local reaction environment around the SrTiO3 nanocrystals. This contributed to a continuous modulation between the surface area and the crystallinity of the photocatalyst. The photocatalytic activities of the nanoporous SrTiO3 samples were evaluated by the degradation of gaseous isopropyl alcohol (IPA). Due to an optimal equilibrium between surface area and crystallinity, a SrTiO3 sample synthesized via adding 40% template (STO-SiO2-40%) showed the highest activity, which achieves 40 and 8 times of enhancement of CO2 evolution in comparison with the sample prepared without template and a commercial nano-SrTiO3, respectively. The photodegradation mechanism of IPA over this sample was also investigated in detail. This synthetic technique is also available to prepare the other nanoporous titanates, such as doped SrTiO3 samples and alkali-metal titanates.
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http://dx.doi.org/10.1021/am506877bDOI Listing
December 2014

Visible-light photodecomposition of acetaldehyde by TiO2-coated gold nanocages: plasmon-mediated hot electron transport via defect states.

Chem Commun (Camb) 2014 Dec 30;50(98):15553-6. Epub 2014 Oct 30.

Environmental Remediation Materials Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.

Skeletal gold nanocages (Au NCs) are synthesized and coated with TiO2 layers (TiO2-Au NCs). The TiO2-Au NCs exhibit enhanced photodecomposition activity toward acetaldehyde under visible light (>400 nm) illumination because hot electrons are generated over the Au NCs by local surface plasmon resonance (LSPR) and efficiently transported across the metal/semiconductor interface via the defect states of TiO2.
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http://dx.doi.org/10.1039/c4cc06229aDOI Listing
December 2014

Efficient photochemical oxygen generation from water by phosphorus-doped H2MoO5.

Chem Commun (Camb) 2014 Oct;50(81):12185-8

International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.

Efficient photochemical oxygen generation is achieved using phosphorus-doped H2MoO5 under visible light illumination. Under optimized conditions, an extremely high apparent quantum yield of 94% is obtained under 410 nm light illumination.
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http://dx.doi.org/10.1039/c4cc06513aDOI Listing
October 2014

Photothermal conversion of CO₂ into CH₄ with H₂ over Group VIII nanocatalysts: an alternative approach for solar fuel production.

Angew Chem Int Ed Engl 2014 Oct 17;53(43):11478-82. Epub 2014 Jul 17.

Environmental Remediation Materials Unit and International Center for Materials Nanoarchitectonics (WPI-MANA), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo 060-0814 (Japan).

The photothermal conversion of CO2 provides a straightforward and effective method for the highly efficient production of solar fuels with high solar-light utilization efficiency. This is due to several crucial features of the Group VIII nanocatalysts, including effective energy utilization over the whole range of the solar spectrum, excellent photothermal performance, and unique activation abilities. Photothermal CO2 reaction rates (mol h(-1) g(-1)) that are several orders of magnitude larger than those obtained with photocatalytic methods (μmol h(-1) g(-1)) were thus achieved. It is proposed that the overall water-based CO2 conversion process can be achieved by combining light-driven H2 production from water and photothermal CO2 conversion with H2. More generally, this work suggests that traditional catalysts that are characterized by intense photoabsorption will find new applications in photo-induced green-chemistry processes.
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http://dx.doi.org/10.1002/anie.201404953DOI Listing
October 2014

Porous-structured Cu2O/TiO2 nanojunction material toward efficient CO2 photoreduction.

Nanotechnology 2014 Apr 26;25(16):165402. Epub 2014 Mar 26.

TU-NIMS Joint Research Center, and Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, People's Republic of China. Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People's Republic of China. Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044, Japan.

Porous-structured Cu2O/TiO2 nanojunction material is successfully fabricated by a facile method via loading Cu2O nanoparticles on the network of a porous TiO2 substrate. The developed Cu2O/TiO2 nanojunction material has a size of several nanometers, in which the p-type Cu2O and n-type TiO2 nanoparticles are closely contacted with each other. The well designed nanojunction structure is beneficial for the charge separation in the photocatalytic reaction. Meanwhile, the porous structure of the Cu2O/TiO2 nanojunction can facilitate the CO2 adsorption and offer more reaction active sites. Most importantly, the gas-phase CO2 photoreduction tests reveal that our developed porous-structured Cu2O/TiO2 nanojunction material exhibits marked photocatalytic activity in the CH4 evolution, about 12, 9, and 7.5 times higher than the pure TiO2, Pt-TiO2, and commercial Degussa P25 TiO2 powders, respectively. The greatly enhanced activity can be attributed to the well designed nanojunction structure combined with the porous structure, which can simultaneously enhance the charge separation efficiency and facilitate the CO2 adsorption.
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http://dx.doi.org/10.1088/0957-4484/25/16/165402DOI Listing
April 2014

Gold-nanorod-photosensitized titanium dioxide with wide-range visible-light harvesting based on localized surface plasmon resonance.

Angew Chem Int Ed Engl 2013 Jun 10;52(26):6689-93. Epub 2013 May 10.

International Center for Materials Nanoarchitectonics and Environmental Remediation Materials Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.

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http://dx.doi.org/10.1002/anie.201300239DOI Listing
June 2013

Chlorine as an indicator in the controllable preparation of active nano-gold catalyst.

Sci Rep 2013 ;3:1503

Centre for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.

The controllable preparation of nano-gold catalyst maintains a challenge. Except the parameters have been revealed before, here we'd like to show that controllable preparation of active nano-gold catalyst can be achieved using chlorine as an indicator. By tracing the chlorine concentration in the washing step, a series of Au/Fe2O3 catalysts were prepared with co-precipitation method. The applying of these catalysts in CO oxidation and reductive nitrobenzene N-alkylation suggested the active catalysts were prepared from solutions containing ~2 ppm chlorine. The catalytic activity dropped dramatically if the chlorine concentration is >4-6 or ≪1 ppm. Extensive characterizations revealed that the active catalyst was composed by nano-gold on the edge of Fe2O3 particle with 8.92 Au-Au coordination numbers. Although the real role of chlorine in the variation of catalyst structure and activity was still ambiguous, the current results should promote the controllable preparation of active nano-Au catalyst.
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http://dx.doi.org/10.1038/srep01503DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3603287PMC
April 2014

A p-type Cr-doped TiO2 photo-electrode for photo-reduction.

Chem Commun (Camb) 2013 Apr;49(33):3440-2

Environmental Remediation Materials Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, Japan.

A p-type Cr-doped TiO2 photo-electrode is fabricated using a pulsed laser deposition method on a Sn doped indium-oxide-coated glass sheet (ITO). The p-type properties of the as-prepared Cr-doped TiO2 photo-electrode are suggested to be attributed to unique substitutional Cr(4+) doping in the TiO2 lattice.
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http://dx.doi.org/10.1039/c3cc40394gDOI Listing
April 2013

Novel chemoselective hydrogenation of aromatic nitro compounds over ferric hydroxide supported nanocluster gold in the presence of CO and H2O.

Chem Commun (Camb) 2009 Feb 17(6):653-5. Epub 2008 Dec 17.

State Key Laboratory for Oxo Synthesis and Selective Oxidation and Centre for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.

Chemoselective hydrogenation of aromatic nitro compounds were first efficiently achieved over Au/Fe(OH)(x) at 100-120 degrees C for 1.5-6 h (depending on different substrates) in the presence of CO and H(2)O.
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http://dx.doi.org/10.1039/b816547eDOI Listing
February 2009

Ferric hydroxide supported gold subnano clusters or quantum dots: enhanced catalytic performance in chemoselective hydrogenation.

Dalton Trans 2008 May 3(19):2542-8. Epub 2008 Apr 3.

Centre for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.

An attempt to prepare ferric hydroxide supported Au subnano clusters via modified co-precipitation without any calcination was made. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) have been employed to study the structure and chemical states of these catalysts. No Au species could be observed in the HRTEM image nor from the XRD pattern, suggesting that the sizes of the Au species in and on the ferric hydroxide support were less than or around 1 nm. Chemoselective hydrogenation of aromatic nitro compounds and alpha,beta-unsaturated aldehydes was selected as a probe reaction to examine the catalytic properties of this catalyst. Under the same reaction conditions, such as 100 degrees C and 1 MPa H2 in the hydrogenation of aromatic nitro compounds, a 96-99% conversion (except for 4-nitrobenzonitrile) with 99% selectivity was obtained over the ferric hydroxide supported Au catalyst, and the TOF values were 2-6 times higher than that of the corresponding ferric oxide supported catalyst with 3-5 nm size Au particles. For further evaluation of this Au catalyst in the hydrogenation of citral and cinnamaldehyde, selectivity towards unsaturated alcohols was 2-20 times higher than that of the corresponding ferric oxide Au catalyst.
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http://dx.doi.org/10.1039/b716870eDOI Listing
May 2008
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