Ni@NiO功能化的SrTiO在全水解中的瞬态行为

Han Kai, Kreuger Tomas, Mei Bastian, Mul Guido

Photocatalytic Synthesis Group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente , Meander 229, P.O. Box 217, 7500 AE Enschede, The Netherlands.

ACS Catal. 2017 Mar 3;7(3):1610-1614. doi: 10.1021/acscatal.6b03662. Epub 2017 Jan 24.

Transients in the composition of Ni@NiO core-shell co-catalysts deposited on SrTiO are discussed on the basis of state-of-the-art continuous analysis of photocatalytic water splitting, and post-XPS and TEM analyses. The formation of excessive hydrogen (H:O ≫ 2) in the initial stages of illumination demonstrates oxidation of Ni(OH) to NiOOH (nickel oxyhydroxide), with the latter catalyzing water oxidation. A disproportionation reaction of Ni and NiOOH, yielding Ni(OH) with residual embedded Ni, occurs when illumination is discontinued, which explains repetitive transients in (excess) hydrogen and oxygen formation when illumination is reinitiated.

基于光催化水分解的最新连续分析、X射线光电子能谱（XPS）和透射电子显微镜（TEM）分析，讨论了沉积在钛酸锶（SrTiO）上的镍@氧化镍（Ni@NiO）核壳共催化剂组成中的瞬态现象。光照初始阶段过量氢气（H:O ≫ 2）的形成表明氢氧化镍（Ni(OH)）被氧化为羟基氧化镍（NiOOH），后者催化水氧化。光照停止时，会发生镍与羟基氧化镍的歧化反应，生成含有残留嵌入镍的氢氧化镍，这解释了重新光照时（过量）氢气和氧气形成的重复瞬态现象。