Ultrathin HNbWO6 nanosheets: facile synthesis and enhanced hydrogen evolution performance from photocatalytic water splitting

2015 ◽  
Vol 51 (82) ◽  
pp. 15125-15128 ◽  
Author(s):  
Yuhao Liu ◽  
Jinhua Xiong ◽  
Shuiguang Luo ◽  
Ruowen Liang ◽  
Na Qin ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Simulated Sunlight ◽  
Facile Synthesis ◽  
Sunlight Irradiation ◽  
Photocatalytic Water Splitting ◽  
Highly Dispersed

Ultrathin monolayer HNbWO6 nanosheets were rapidly synthesised with triethanolamine as a stripping agent in just a few minutes. These obtained highly dispersed nanosheets suspensions exhibit an efficient photocatalytic H2 evolution performance under simulated sunlight irradiation.

Photoelectrochemical Properties of Surface-Modified ZnSe:Cu(In,Ga)Se2 Photocathodes for Efficient and Durable Overall Water Splitting

2018 ◽  
Vol MA2018-01 (31) ◽  
pp. 1922-1922
Author(s):  
Hiroyuki Kaneko ◽  
Tsutomu Minegishi ◽  
Kazunari Domen
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
List Type ◽  
Simulated Sunlight ◽  
Current Time ◽  
Overall Water Splitting ◽  
Potassium Phosphate Buffer Solution ◽  
Surface Modified

Overall water splitting using a photoelectrochemical (PEC) cell composed of a photocathode and photoanode connected in a series is an attractive method to produce hydrogen from water under sunlight. Because driving forces of two photoelectrodes are combined for the water splitting reaction, narrow-gap materials can be used to achieve high solar-to-hydrogen conversion efficiency (STH). However, the STHs obtained from a PEC cell without any external bias voltage reported so far have been less than 1%. This is because of insufficient onset potentials and photocurrent values of photoelectrodes. For the sake of overcoming the drawbacks, (ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15 ((ZnSe)0.85(CIGS)0.15) thin film photocathodes have recently been developed and reported to show a high onset potential of 0.89 VRHE and long absorption edge of 850-900 nm.2 These properties are suitable for use in the PEC cell. (ZnSe)0.85(CIGS)0.15 thin films are prepared by co-evaporation onto Mo-coated soda-lime glass substrates. Subsequently, CdS, a binary of Mo/Ti and Pt are deposited onto the photocathode surface as a buffer layer, surface conductor and hydrogen evolution reaction (HER) catalyst, respectively.3 The surface-modified (ZnSe)0.85(CIGS)0.15 photocathodes show a relatively high photocurrent value of 12 mA cm-2 at 0 VRHE and sufficient stability in a span of hours at potentials of more negative than 0.5 VRHE under simulated sunlight in a neutral potassium phosphate buffer solution.4 However, at potentials more positive than 0.5 VRHE, the photocurrent value attributed to HER dramatically decreases by half in just one hour mainly due to self-oxidation of the surface sulfide layer, accompanying detachment of the Mo/Ti and Pt at the surface. The poor stability at the positive potentials has made it difficult to construct durable PEC cell using the photocathodes. In this work, effects of surface modifications onto PEC properties of (ZnSe)0.85(CIGS)0.15 photocathodes are investigated. For the sake of suppressing the surface corrosion, the CdS layer was passivated with In2S3, which was formed by using chemical bath deposition (CBD).5 Figure 1 shows the current-time curves of the surface-modified (ZnSe)0.85(CIGS)0.15 photocathodes at 0.6 VRHE under simulated sunlight. Without the CBD treatment, the photocurrent value decreased by 50% in one hour under light irradiation. On the other hand, the In2S3-modified photocathode showed relatively stable PEC HER and the decline of the photocurrent value in one hour was decreased to 25%. It is highly possible that the improvement of stability originates from low solubility of indium oxide or hydroxide generated by the self-oxidation process, while the cadmium oxide and hydroxide are relatively soluble, which can cause corrosion of the surface. Furthermore, effects of oxide-coating onto the stability of the (ZnSe)0.85(CIGS)0.15 photocathode during PEC hydrogen evolution have also been investigated. Among various kinds of coating processes, direct formation of the oxide layer by photoelectrodeposition without annealing the photocathode is an effective method without exerting a bad influence on the underlying sulfide and selenide materials. In the presentation, the details of preparation conditions and PEC properties will be discussed. References J. W. Ager, M. R. Shaner, K. A. Walczak, I. D. Sharp and S. Ardo, Energy Environ. Sci. 2015, 8, 2811–2824. H. Kaneko, T. Minegishi, M. Nakabayashi, N. Shibata, Y. Kuang, T. Yamada and K. Domen, Adv. Funct. Mater. 2016, 26, 4570–4577. H. Kumagai, T. Minegishi, N. Sato, T. Yamada, J. Kubota and K. Domen, J. Mater. Chem. A 2015, 3, 8300–8307. H. Kaneko, T. Minegishi, M. Nakabayashi, N. Shibata and K. Domen, Angew. Chemie Int. Ed. 2016, 55, 15329–15333. F. Jiang, Gunawan, T. Harada, Y. Kuang, T. Minegishi, K. Domen and S. Ikeda, J. Am. Chem. Soc. 2015, 137, 13691–13697. Figure 1

scholarly journals Mechanism for spontaneous oxygen and hydrogen evolution reactions on CoO nanoparticles

2019 ◽  
Vol 7 (12) ◽  
pp. 6708-6719 ◽  
Author(s):  
Kyoung-Won Park ◽  
Alexie M. Kolpak
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
High Efficiency ◽  
Applied Bias ◽  
Co Catalyst ◽  
Photocatalytic Water Splitting ◽  
Overall Water Splitting ◽  
Nanoparticle Suspensions ◽  
Hydrogen Evolution Reactions ◽  
Coo Nanoparticles

Overall photocatalytic water splitting with a high efficiency has recently been observed for CoO nanoparticle suspensions in the absence of an applied bias or co-catalyst. This study clarifies the mechanism of spontaneous overall water splitting with the prominent efficiency observed on the CoO nanoparticle.

Phosphorus containing materials for photocatalytic hydrogen evolution

2017 ◽  
Vol 19 (3) ◽  
pp. 588-613 ◽  
Author(s):  
Zhuofeng Hu ◽  
Zhurui Shen ◽  
Jimmy C. Yu
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Clean Energy ◽  
Renewable Source ◽  
Photocatalytic Hydrogen Evolution ◽  
Photocatalytic Water Splitting ◽  
Phosphorus Containing

Hydrogen from photocatalytic water splitting is a sustainable and renewable source of clean energy.

Defective graphitic carbon nitride synthesized by controllable co-polymerization with enhanced visible light photocatalytic hydrogen evolution

2017 ◽  
Vol 7 (2) ◽  
pp. 452-458 ◽  
Author(s):  
Mei Zhang ◽  
Yanyan Duan ◽  
Hanzhong Jia ◽  
Fu Wang ◽  
Lan Wang ◽  
...  
Keyword(s):  
Visible Light ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Photocatalytic Hydrogen Evolution ◽  
Photocatalytic Water Splitting ◽  
Visible Light Photocatalytic

Schematic illustration of modified g-C3N4for visible-light photocatalytic water splitting to hydrogen. The CN-DPT shows remarkably enhanced hydrogen evolution performance.

Hydrogen production by photocatalytic water splitting of aqueous hydrogen iodide over Pt/alkali metal tantalates

2019 ◽  
Vol 3 (11) ◽  
pp. 3021-3028 ◽  
Author(s):  
Hidehisa Hagiwara ◽  
Ittoku Nozawa ◽  
Katsuaki Hayakawa ◽  
Tatsumi Ishihara
Keyword(s):  
Hydrogen Production ◽  
Alkali Metal ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Hydrogen Iodide ◽  
Photocatalytic Water Splitting

Reduction of the hydrogen evolution overpotential and durability in aqueous HI are important factors for the cocatalyst loaded onto KTaO3.

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