Lin Hsin-Yu, Lin Yu-Cheng
Department of Materials Science and Engineering, National Dong Hwa University, Hualien, 97401, Taiwan.
J Nanosci Nanotechnol. 2020 Feb 1;20(2):1224-1231. doi: 10.1166/jnn.2020.16972.
The layered potassium niobate, K₄NbO, is known as a photocatalyst for hydrogen production from water splitting under UV light. Here we show that potassium niobate nanosheets can be obtained by exfoliation of K₄NbO followed by proton exchange. Photocatalytic water splitting has been improved in this work by loading Rh nanoparticles as cocatalyst. The catalysts were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy analysis (XPS), and ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Their photocatalytic activities were in (i) an aqueous MeOH, used as sacrificial hole scavengers for hydrogen production and (ii) pure water for hydrogen and oxygen production under UV light irradiation. The potassium niobate nanosheets with uniform dispersion of Rh nanoparticles exhibited a very high photocatalytic overall water splitting activity, where the H₂ production and O₂ production rate were 142 mol h g and 68 mol h g, which was about 10 times higher than that exhibited by the origin K₄NbO photocatalyst.
层状铌酸钾K₄NbO被认为是一种在紫外光下通过水分解制氢的光催化剂。在此我们表明，铌酸钾纳米片可通过K₄NbO剥离然后进行质子交换获得。在这项工作中，通过负载Rh纳米颗粒作为助催化剂提高了光催化水分解性能。采用粉末X射线衍射（XRD）、X射线光电子能谱分析（XPS）、紫外可见光谱（UV-vis）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对催化剂进行了表征。它们的光催化活性体现在：（i）在用作产氢牺牲空穴清除剂的甲醇水溶液中，以及（ii）在紫外光照射下用于产氢和产氧的纯水中。具有均匀分散的Rh纳米颗粒的铌酸钾纳米片表现出非常高的光催化全水分解活性，其中产氢速率和产氧速率分别为142 μmol h⁻¹ g⁻¹和68 μmol h⁻¹ g⁻¹，这比原始的K₄NbO光催化剂高出约10倍。
