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1.
Minghui Liu Prof. Guigang Zhang Xiaocong Liang Dr. Zhiming Pan Dr. Dandan Zheng Prof. Sibo Wang Prof. Zhiyang Yu Yidong Hou Prof. Xinchen Wang 《Angewandte Chemie (International ed. in English)》2023,62(37):e202304694
In situ photo-deposition of both Pt and CoOx cocatalysts on the facets of poly (triazine imide) (PTI) crystals has been developed for photocatalytic overall water splitting. However, the undesired backward reaction (i.e., water formation) on the noble Pt surface is a spontaneously down-hill process, which restricts their efficiency to run the overall water splitting reaction. Herein, we demonstrate that the efficiency for photocatalytic overall water splitting could be largely promoted by the decoration of Rh/Cr2O3 and CoOx as H2 and O2 evolution cocatalysts, respectively. Results reveal that the dual cocatalysts greatly extract charges from bulk to surface, while the Rh/Cr2O3 cocatalyst dramatically restrains the backward reaction, achieving an apparent quantum efficiency (AQE) of 20.2 % for the photocatalytic overall water splitting reaction. 相似文献
2.
Efficient Visible‐Light‐Driven Z‐Scheme Overall Water Splitting Using a MgTa2O6−xNy /TaON Heterostructure Photocatalyst for H2 Evolution 下载免费PDF全文
Shanshan Chen Yu Qi Dr. Takashi Hisatomi Qian Ding Tomohiro Asai Zheng Li Dr. Su Su Khine Ma Prof. Fuxiang Zhang Prof. Kazunari Domen Prof. Can Li 《Angewandte Chemie (International ed. in English)》2015,54(29):8498-8501
An (oxy)nitride‐based heterostructure for powdered Z‐scheme overall water splitting is presented. Compared with the single MgTa2O6?xNy or TaON photocatalyst, a MgTa2O6?xNy /TaON heterostructure fabricated by a simple one‐pot nitridation route was demonstrated to effectively suppress the recombination of carriers by efficient spatial charge separation and decreased defect density. By employing Pt‐loaded MgTa2O6?xNy /TaON as a H2‐evolving photocatalyst, a Z‐scheme overall water splitting system with an apparent quantum efficiency (AQE) of 6.8 % at 420 nm was constructed (PtOx‐WO3 and IO3?/I? pairs were used as an O2‐evolving photocatalyst and a redox mediator, respectively), the activity of which is circa 7 or 360 times of that using Pt‐TaON or Pt‐MgTa2O6?xNy as a H2‐evolving photocatalyst, respectively. To the best of our knowledge, this is the highest AQE among the powdered Z‐scheme overall water splitting systems ever reported. 相似文献
3.
Plasmon‐Assisted Water Splitting Using Two Sides of the Same SrTiO3 Single‐Crystal Substrate: Conversion of Visible Light to Chemical Energy 下载免费PDF全文
Yuqing Zhong Prof. Kosei Ueno Yuko Mori Dr. Xu Shi Dr. Tomoya Oshikiri Prof. Kei Murakoshi Prof. Haruo Inoue Prof. Hiroaki Misawa 《Angewandte Chemie (International ed. in English)》2014,53(39):10350-10354
A plasmon‐induced water splitting system that operates under irradiation by visible light was successfully developed; the system is based on the use of both sides of the same strontium titanate (SrTiO3) single‐crystal substrate. The water splitting system contains two solution chambers to separate hydrogen (H2) and oxygen (O2). To promote water splitting, a chemical bias was applied by regulating the pH values of the chambers. The quantity of H2 evolved from the surface of platinum, which was used as a reduction co‐catalyst, was twice the quantity of O2 evolved from an Au‐nanostructured surface. Thus, the stoichiometric evolution of H2 and O2 was clearly demonstrated. The hydrogen‐evolution action spectrum closely corresponds to the plasmon resonance spectrum, indicating that the plasmon‐induced charge separation at the Au/SrTiO3 interface promotes water oxidation and the subsequent reduction of a proton on the backside of the SrTiO3 substrate. The chemical bias is significantly reduced by plasmonic effects, which indicates the possibility of constructing an artificial photosynthesis system with low energy consumption. 相似文献
4.
Jun Wang Wenzhao Li Chunying Yu Yanxin Chen Yingzhen Zhang 《Reaction Kinetics and Catalysis Letters》1997,62(2):217-224
Recucibility of Mo species in Pt/MoO3 and PtMo/Al2O3 has been investigated by temperature-programmed reduction (TPR), temperature-programmed desorption of hydrogen (H2-TPD) and temperature programmed electronic conductivity (TPEC) techniques. In Pt/MoO3 at H2 atmosphere, it was found by TPEC and TPR that, a slight amount of Pt could activate the transfer of the species and H atoms
between H2 and MoO3, and thus accelerate the reduction of MoO3. In PtMo/Al2O3, TPR and H2-TPD revealed that the reduction of surface Mo species could also be facilitated by Pt. Two kinds of hydrogen molybdenum species
were proposed on the surface of the catalyst after prereduction. 相似文献
5.
Yige Deng Song Shu Ningjie Fang Ruobing Wang Yinghao Chu Zhaobing Liu Wanglai Cen 《中国化学快报》2023,34(2):107323-261
Photocatalytic hydrogen evolution from water splitting is a promising strategy for realizing the vision of carbon neutrality.Herein,a novel Sr Ti O3-Sr CO3n-n heterojunction was used for the first time for water splitting to generate H2.The heterojunction was synthesized by a soft chemical one-pot hydrothermal method.The Sr Ti O3-Sr CO3loading with 3 wt%Pt shows the maximum photocatalytic H2evolution rate of3.62 mmol h-1 相似文献
6.
The effects of H2 and H2 + O2 gas mixtures of varying composition on the state of the surface of the Pt/MoO3 model catalyst prepared by vacuum deposition of platinum on oxidized molybdenum foil were investigated by X-ray photoelectron spectroscopy (XPS) at room temperature and a pressure of 5–150 Torr. For samples with a large Pt/Mo ratio, the XP spectrum of large platinum particles showed that the effect of hydrogen-containing mixtures on the catalyst was accompanied by the reduction of molybdenum oxide. This effect results from the activation of molecular hydrogen due to the dissociation on platinum particles and subsequent spill-over of hydrogen atoms on the support. The effect was not observed at low platinum contents in the model catalyst (i.e., for small Pt particles). It is assumed for the catalyst that the loss of its hydrogen-activating ability is a consequence of the formation of platinum hydride. Possible participation of platinum hydride as intermediate in hydrogen oxidation to H2O2 is discussed. 相似文献
7.
Photocatalyst Materials for Water Splitting 总被引:4,自引:0,他引:4
Akihiko Kudo 《Catalysis Surveys from Asia》2003,7(1):31-38
Various photocatalyst materials developed by the group of the present author are described. Alkali and alkaline earth tantalates have arisen as a new group of photocatalyst materials for splitting of water into H2 and O2 under ultraviolet irradiation. They showed activities even without co-catalysts such as Pt, being different from titanate photocatalysts. When NiO co-catalysts were loaded on the tantalate photocatalysts, the photocatalytic activities were markedly increased. Among the tantalates, NiO/NaTaO3 doped with La showed the highest activity. BiVO4, AgNO3, and TiO2 co-doped with Cr and Sb photocatalysts showed high activities for O2 evolution in the presence of a sacrificial reagent (Ag+) under visible light irradiation ( > 420 nm). Pt/SrTiO3 co-doped with Cr and Sb or Ta, Pt/NaInS2, and Pt/AgInZn7S9 photocatalysts showed high activities for H2 evolution from aqueous solutions containing reducing reagents under visible light irradiation. Furthermore, Cu- or Ni-doped ZnS photocatalysts showed H2 evolution activities even without co-catalysts such as Pt. 相似文献
8.
A Complex Perovskite‐Type Oxynitride: The First Photocatalyst for Water Splitting Operable at up to 600 nm 下载免费PDF全文
Dr. Chengsi Pan Dr. Tsuyoshi Takata Mamiko Nakabayashi Dr. Takao Matsumoto Prof. Naoya Shibata Prof. Yuichi Ikuhara Prof. Kazunari Domen 《Angewandte Chemie (International ed. in English)》2015,54(10):2955-2959
One of the simplest methods for splitting water into H2 and O2 with solar energy entails the use of a particulate‐type semiconductor photocatalyst. To harness solar energy efficiently, a new water‐splitting photocatalyst that is active over a wider range of the visible spectrum has been developed. In particular, a complex perovskite‐type oxynitride, LaMgxTa1?xO1+3xN2?3x (x≥1/3), can be employed for overall water splitting at wavelengths of up to 600 nm. Two effective strategies for overall water splitting were developed. The first entails the compositional fine‐tuning of a photocatalyst to adjust the bandgap energy and position by forming a series of LaMgxTa1?xO1+3xN2?3x solid solutions. The second method is based on the surface coating of the photocatalyst with a layer of amorphous oxyhydroxide to control the surface redox reactions. By combining these two strategies, the degradation of the photocatalyst and the reverse reaction could be prevented, resulting in successful overall water splitting. 相似文献
9.
Yanze Wei Jiangyan Wang Ranbo Yu Jiawei Wan Dan Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1436-1440
Constructing hollow multi‐shelled structures (HoMSs) has a significant effect on promoting light absorption property of catalysts and enhancing their performance in solar energy conversion applications. A facile hydrothermal method is used to design the SrTiO3?TiO2 heterogeneous HoMSs by hydrothermal crystallization of SrTiO3 on the surface of the TiO2 HoMSs, which will realize a full coverage of SrTiO3 on the TiO2 surface and construct the SrTiO3/TiO2 junctions. The broccoli‐like SrTiO3?TiO2 heterogeneous HoMSs exhibited a fourfold higher overall water splitting performance of 10.6 μmol h?1 for H2 production and 5.1 μmol h?1 for O2 evolution than that of SrTiO3 nanoparticles and the apparent quantum efficiency (AQE) of 8.6 % at 365 nm, which can be mainly attributed to 1) HoMS increased the light absorption ability of the constructed photocatalysts and 2) the SrTiO3?TiO2 junctions boosted the separation efficiency of the photogenerated charge carriers. 相似文献
10.
以质子化层状钙钛矿氧化物H1.9K0.3La0.5Bi0.1Ta2O7 (HKLBT)作为产氢催化剂, Pt/WO3作为产氧催化材料进行Z 型体系下完全分解水反应. 考察了不同载流子传递介质及不同载流子浓度对反应活性的影响. 结果表明, 以Fe2+/Fe3+为载流子传递介质时可以实现水的完全分解(H2/O2体积比为2:1), 8 mmol·L-1的FeCl3作为初始载流子传递介质时, 产氢、产氧活性分别为66.8和31.8 μmol·h-1, 氢氧体积比为2.1:1. 受光催化材料对载流子传递介质氧化还原速度的限制, 过高的载流子传递介质浓度并不能提高光催化活性. 相似文献
11.
Intercalation of Highly Dispersed Metal Nanoclusters into a Layered Metal Oxide for Photocatalytic Overall Water Splitting 下载免费PDF全文
Takayoshi Oshima Dr. Daling Lu Prof. Dr. Osamu Ishitani Prof. Dr. Kazuhiko Maeda 《Angewandte Chemie (International ed. in English)》2015,54(9):2698-2702
Metal nanoclusters (involving metals such as platinum) with a diameter smaller than 1 nm were deposited on the interlayer nanospace of KCa2Nb3O10 using the electrostatic attraction between a cationic metal complex (e.g., [Pt(NH3)4]Cl2) and a negatively charged two‐dimensional Ca2Nb3O10? sheet, without the aid of any additional reagent. The material obtained possessed eight‐fold greater photocatalytic activity for water splitting into H2 and O2 under band‐gap irradiation than the previously reported analog using a RuO2 promoter. This study highlighted the superior functionality of Pt nanoclusters with diameters smaller than 1 nm for photocatalytic overall water splitting. This material shows the greatest efficiency among nanosheet‐based photocatalysts reported to date. 相似文献
12.
Hidehisa Hagiwara Dr. Takanori Inoue Prof. Dr. Kenji Kaneko Prof. Dr. Tatsumi Ishihara Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(46):12862-12870
The mechanism of photocatalytic splitting of H2O into H2 and O2 on Pt/KTa(Zr)O3 modified with various porphyrinoids was investigated. The photocatalytic activity of KTaO3 catalysts is improved by dye modification. Cyanocobalamin (vitamin B12) is the most effective for improving water‐splitting activity, and the formation rates of H2 and O2 achieved values of 575 and 280 μmol gcat.?1 h?1, respectively. X‐ray photoelectron spectroscopy spectra of KTa(Zr)O3 photocatalysts showed that Pt loaded onto dye‐modified KTaO3 was slightly oxidized and had low catalytic activity for the H2 oxidation reaction. Photoluminescence (PL) spectra of KTaO3 catalysts suggested that excitation energy was transferred between KTaO3, tetraphenylporphyrinatochromium(III) (Cr–TPP), and the Pt cocatalyst. The wavelength dependence of the activity of dye‐modified KTa(Zr)O3 photocatalysts indicated that excitation of both KTa(Zr)O3 and the dye was essential for achieving increased photocatalytic activity. This result suggests that two‐step excitation occurred in the dye‐modified KTa(Zr)O3 photocatalysts. Because the lifetime of the charge‐separated state increased, this study reveals that modification with porphyrinoids is effective for increasing water‐splitting activity. 相似文献
13.
Yeilin Ham Dr. Kazuhiko Maeda Dr. Dongkyu Cha Dr. Kazuhiro Takanabe Prof. Dr. Kazunari Domen 《化学:亚洲杂志》2013,8(1):218-224
Poly(triazine imide) was synthesized with incorporation of Li+ and Cl? ions (PTI/Li+Cl?) to form a carbon nitride derivative. The synthesis of this material by the temperature‐induced condensation of dicyandiamide was examined both in a eutectic mixture of LiCl–KCl and without KCl. On the basis of X‐ray diffraction measurements of the synthesized materials, we suggest that a stoichiometric amount of LiCl is necessary to obtain the PTI/Li+Cl? phase without requiring the presence of KCl at 873 K. PTI/Li+Cl? with modification by either Pt or CoOx as cocatalyst photocatalytically produced H2 or O2, respectively, from water. The production of H2 or O2 from water indicates that the valence and conduction bands of PTI/Li+Cl? were properly located to achieve overall water splitting. The treatment of PTI/Li+Cl? with [Pt(NH3)4]2+ cations enabled the deposition of Pt through ion exchange, demonstrating photocatalytic activity for H2 evolution, while treatment with [PtCl6]2? anions resulted in no Pt deposition. This was most likely because of the preferential exchange between Li+ ions and [Pt(NH3)4]2+ cations. 相似文献
14.
Overall Water Splitting on the Transition‐Metal Oxynitride Photocatalyst LaMg1/3Ta2/3O2N over a Large Portion of the Visible‐Light Spectrum 下载免费PDF全文
Dr. Chengsi Pan Dr. Tsuyoshi Takata Prof. Kazunari Domen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1854-1862
One of the main targets of studies on water splitting photocatalysts is to develop semiconductor materials with narrower bandgaps capable of overall water splitting for efficient harvesting of solar energy. A series of transition‐metal oxynitrides, LaMgxTa1?xO1+3xN2?3x (x≥1/3), with a complex perovskite structure was reported as the first example of overall water splitting operable at up to 600 nm. The photocatalytic behavior of LaMg1/3Ta2/3O2N was investigated in detail in order to optimize photocatalyst preparation and water‐splitting activity. Various attempts exploring photocatalyst preparation steps, that is, cocatalyst selection, coating material and method, and synthesis method for the oxide precursor, revealed photocatalyst structures necessary for achieving overall water splitting. Careful examination of photocatalyst preparation procedures likely enhanced the quality of the produced photocatalyst, leading to a more homogeneous coating quality and semiconductor particles with fewer defects. Thus, the photocatalytic activity for water splitting on LaMg1/3Ta2/3O2N was largely enhanced. 相似文献
15.
The interactions of water molecule with platinum dioxygen complex and dioxide molecule are investigated by means of matrix isolation infrared spectroscopy and density functional calculations. The platinum atoms reacted with dioxygen to form the previously reported Pt(O2) complex. The Pt(O2) complex reacted with water molecule to give the Pt(O2)–H2O complex, which was characterized to involve hydrogen bonding between one O atom of Pt(O2) and one H atom of H2O (structure A ). Upon visible light irradiation, the hydrogen bonded Pt(O2)???HOH complex rearranged to another Pt(O2)–H2O isomer (structure B ), which involves (O2)Pt???OH2 interaction. The Pt(O2)–H2O complex in structure B can be isomerized to the weakly bound platinum dioxide‐water complex (structure C ) under UV irradiation. 相似文献
16.
Dr. Ming Xiang Prof. Dr. Zhihua Xu Dr. Jinghao Wang Xiaoqiu Yang Dr. Zhaoxiong Yan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(27):7502-7506
Coupling the H2 evolution reaction in water with thermodynamically favorable organic oxidation reactions is highly desirable, because it can enhance the energy conversion efficiency compared with electrocatalytic water splitting, and produce value-added chemicals instead of O2 in the anodic reaction. Herein, Co3O4 nanoribbon arrays in situ grown on nickel foam (Co3O4@NF) was employed as an effective electrocatalyst for the selective oxidation of tetrahydroisoquinolines (THIQs). Various value-added semi-dehydrogenation products including dihydroisoquinolines with electro-deficient or -rich groups could be obtained with moderate yields and faradaic efficiencies. Benefitting from the rich surface active sites of Co3O4@NF, a two-electrode (Co3O4@NF||Pt) electrolytic system drove a benchmark current density of 10 mA cm−2 at a cell voltage as low as 1.446 V in 1.0 M KOH aqueous solution containing 0.02 M THIQ, which was reduced by 174 mV in comparison with that of overall water splitting. 相似文献
17.
Ronghua Li Tsuyoshi Takata Beibei Zhang Chao Feng Qianbao Wu Chunhua Cui Zemin Zhang Kazunari Domen Yanbo Li 《Angewandte Chemie (International ed. in English)》2023,62(49):e202313537
Overall water splitting (OWS) using semiconductor photocatalysts is a promising method for solar fuel production. Achieving a high quantum efficiency is one of the most important prerequisites for photocatalysts to realize high solar-to-fuel efficiency. In a recent study (Nature 2020 , 58, 411–414), a quantum efficiency of almost 100 % has been achieved in an aluminum-doped strontium titanate (SrTiO3 : Al) photocatalyst. Herein, using the SrTiO3 : Al as a model photocatalyst, we reveal the criteria for efficient photocatalytic water splitting by investigating the carrier dynamics through a comprehensive photoluminescence study. It is found that the Al doping suppresses the generation of Ti3+ recombination centers in SrTiO3, the surface band bending facilitates charge separation, and the in situ photo-deposited Rh/Cr2O3 and CoOOH co-catalysts render efficient charge extraction. By suppressing photocarrier recombination and establishing a facile charge separation and extraction mechanism, high quantum efficiency can be achieved even on photocatalysts with a very short (sub-ns) intrinsic photocarrier lifetime, challenging the belief that a long carrier lifetime is a fundamental requirement. Our findings could provide guidance on the design of OWS photocatalysts toward more efficient solar-to-fuel conversion. 相似文献
18.
Electrodeposited Cobalt‐Phosphorous‐Derived Films as Competent Bifunctional Catalysts for Overall Water Splitting 下载免费PDF全文
Nan Jiang Dr. Bo You Meili Sheng Dr. Yujie Sun 《Angewandte Chemie (International ed. in English)》2015,54(21):6251-6254
One of the challenges to realize large‐scale water splitting is the lack of active and low‐cost electrocatalysts for its two half reactions: H2 and O2 evolution reactions (HER and OER). Herein, we report that cobalt‐phosphorous‐derived films (Co‐P) can act as bifunctional catalysts for overall water splitting. The as‐prepared Co‐P films exhibited remarkable catalytic performance for both HER and OER in alkaline media, with a current density of 10 mA cm?2 at overpotentials of ?94 mV for HER and 345 mV for OER and Tafel slopes of 42 and 47 mV/dec, respectively. They can be employed as catalysts on both anode and cathode for overall water splitting with 100 % Faradaic efficiency, rivalling the integrated performance of Pt and IrO2. The major composition of the as‐prepared and post‐HER films are metallic cobalt and cobalt phosphide, which partially evolved to cobalt oxide during OER. 相似文献
19.
N,N-Bis(3,5-dimethylpyrazol-1-yl)methane (H2CPz'2) reacts with the hexacarbonyls of chromium, molybdenum, and tungsten to give cis-(H2CPz'2)M(CO)4 derivatives with M=Cr, Mo, W. The direct allyl bromination of these complexes is also investigated and only the molybdenum complex is converted into (H2CPz'2)Mo(CO)2(π-C3H3)(Br). 相似文献
20.
Van der Waals Heterostructures Comprised of Ultrathin Polymer Nanosheets for Efficient Z‐Scheme Overall Water Splitting 下载免费PDF全文
Lei Wang Dr. Xusheng Zheng Liang Chen Prof. Yujie Xiong Prof. Hangxun Xu 《Angewandte Chemie (International ed. in English)》2018,57(13):3454-3458
Inspired by natural photosynthesis, Z‐scheme photocatalytic systems are very appealing for achieving efficient overall water splitting. Developing metal‐free Z‐scheme photocatalysts for overall water splitting, however, still remains challenging. The construction of polymer‐based van der Waals heterostructures as metal‐free Z‐scheme photocatalytic systems for overall water splitting is described using aza‐fused microporous polymers (CMP) and C2N ultrathin nanosheets as O2‐ and H2‐evolving catalysts, respectively. Although neither polymer is able to split pure water using visible light, a 2:1 stoichiometric ratio of H2 and O2 was observed when aza‐CMP/C2N heterostructures were used. A solar‐to‐hydrogen conversion efficiency of 0.23 % was determined, which could be further enhanced to 0.40 % by using graphene as the solid electron mediator to promote the interfacial charge‐transfer process. This study highlights the potential of polymer photocatalysts for overall water splitting. 相似文献