CuO纳米阵列结构光阴极的制备及其光电化学分解水的性能

用原位基体加热反应磁控溅射方法制备具有强捕光和电荷分离能力的CuO纳米阵列(CuO NAs)光阴极,并改变氧分压、基底温度、腔体压力以及溅射时间等参数调控其相组成、晶体形貌、晶体生长取向、晶面暴露、厚度以及电子结构。结果表明,结构优化的CuO NAs光阴极,其光电流密度可达2.4 mA·cm^-2。     

Phosphorus‐Rich Colloidal Cobalt Diphosphide (CoP2) Nanocrystals for Electrochemical and Photoelectrochemical Hydrogen Evolution

Developing earth‐abundant and efficient electrocatalysts for photoelectrochemical water splitting is critical to realizing a high‐performance solar‐to‐hydrogen energy conversion process. Herein, phosphorus‐rich colloidal cobalt diphosphide nanocrystals (CoP₂ NCs) are synthesized via hot injection. The CoP₂ NCs show a Pt‐like hydrogen evolution reaction (HER) electrocatalytic activity in acidic solution with a small overpotential of 39 mV to achieve ?10 mA cm^?2 and a very low Tafel slope of 32 mV dec^?1. Density functional theory (DFT) calculations reveal that the high P content both physically separates Co atoms to prevent H from over binding to multiple Co atoms, while simultaneously stabilizing H adsorbed to single Co atoms. The catalytic performance of the CoP₂ NCs is further demonstrated in a metal–insulator–semiconductor photoelectrochemical device consisting of bottom p‐Si light absorber, atomic layer deposition Al–ZnO passivation layers, and the CoP₂ cocatalyst. The p‐Si/AZO/TiO₂/CoP₂ photocathode shows a photocurrent density of ?16.7 mA cm^?2 at 0 V versus reversible hydrogen electrode (RHE) and an output photovoltage of 0.54 V. The high performance and stability are attributed to the junction between p‐Si and AZO, the corrosion‐resistance of the pinhole‐free TiO₂ protective layer, and the fast HER kinetics of the CoP₂ NCs.     

3D FTO/FTO‐Nanocrystal/TiO2 Composite Inverse Opal Photoanode for Efficient Photoelectrochemical Water Splitting

A 3D fluorine‐doped SnO₂ (FTO)/FTO‐nanocrystal (NC)/TiO₂ inverse opal (IO) structure is designed and fabricated as a new “host and guest” type of composite photoanode for efficient photoelectrochemical (PEC) water splitting. In this novel photoanode design, the highly conductive and porous FTO/FTO‐NC IO acts as the “host” skeleton, which provides direct pathways for faster electron transport, while the conformally coated TiO₂ layer acts as the “guest” absorber layer. The unique composite IO structure is fabricated through self‐assembly of colloidal spheres template, a hydrothermal method and atomic layer deposition (ALD). Owing to its large surface area and efficient charge collection, the FTO/FTO‐NC/TiO₂ composite IO photoanode shows excellent photocatalytic properties for PEC water splitting. With optimized dimensions of the SnO₂ nanocrystals and the thickness of the ALD TiO₂ absorber layers, the 3D FTO/FTO‐NC/TiO₂ composite IO photoanode yields a photocurrent density of 1.0 mA cm^?2 at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5 illumination, which is four times higher than that of the FTO/TiO₂ IO reference photoanode.     

Sb‐Doped SnO2 Nanorods Underlayer Effect to the α‐Fe2O3 Nanorods Sheathed with TiO2 for Enhanced Photoelectrochemical Water Splitting

Here, a Sb‐doped SnO₂ (ATO) nanorod underneath an α‐Fe₂O₃ nanorod sheathed with TiO₂ for photoelectrochemical (PEC) water splitting is reported. The experimental results, corroborated with theoretical analysis, demonstrate that the ATO nanorod underlayer effect on the α‐Fe₂O₃ nanorod sheathed with TiO₂ enhances the PEC water splitting performance. The growth of the well‐defined ATO nanorods is reported as a conductive underlayer to improve α‐Fe₂O₃ PEC water oxidation performance. The α‐Fe₂O₃ nanorods grown on the ATO nanorods exhibit improved performance for PEC water oxidation compared to α‐Fe₂O₃ grown on flat fluorine‐doped tin oxide glass. Furthermore, a simple and facile TiCl₄ chemical treatment further introduces TiO₂ passivation layer formation on the α‐Fe₂O₃ to reduce surface recombination. As a result, these unique nanostructures show dramatically improved photocurrent density (139% higher than that of the pure hematite nanorods).