Kao Kun-Che, Kuroiwa Yoshinori, Nishi Hiroyasu, Tatsuma Tetsu
Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
Phys Chem Chem Phys. 2017 Nov 29;19(46):31429-31435. doi: 10.1039/c7cp06527b.
Metal-semiconductor plasmonic nanostructures are capable of converting light energy through plasmon-induced charge separation (PICS), providing fruitful new strategies to utilize solar energy in various fields, including photocatalysis. Here, we enhance the PICS efficiencies for hydrogen evolution from water at a Pt cathode coupled with a TiO/Au photoanode by coating the TiO/Au with a p-type NiO layer on which a Pt co-catalyst is deposited. PICS occurs at the Au-TiO interface under visible light. The electrons injected from the Au nanoparticles into TiO are transported to the Pt cathode and cause hydrogen evolution from water, the action spectrum of which matches the plasmonic extinction spectrum of the Au nanoparticles. The NiO layer extracts the separated positive charges from the Au nanoparticles, accumulates the charges and drives methanol oxidation at the Pt co-catalyst on NiO with the positive charges. As a result of the introduction of the Pt-modified NiO layer, the rates of methanol oxidation and accompanying hydrogen evolution at zero bias voltage were improved by ∼3.5 times. The NiO layer may also protect the Au nanoparticles from self-oxidation.
金属-半导体等离子体纳米结构能够通过等离子体诱导电荷分离（PICS）来转换光能，为包括光催化在内的各个领域利用太阳能提供了丰富的新策略。在此，我们通过在TiO/Au上涂覆一层p型NiO层并在其上沉积Pt助催化剂，提高了与TiO/Au光阳极耦合的Pt阴极上从水中析氢的PICS效率。在可见光下，PICS发生在Au-TiO界面。从Au纳米颗粒注入到TiO中的电子被传输到Pt阴极并导致从水中析氢，其作用光谱与Au纳米颗粒的等离子体消光光谱相匹配。NiO层从Au纳米颗粒中提取分离出的正电荷，积累电荷并驱动NiO上Pt助催化剂处的甲醇氧化反应，利用这些正电荷。由于引入了Pt修饰的NiO层，在零偏压下甲醇氧化和伴随的析氢速率提高了约3.5倍。NiO层还可以保护Au纳米颗粒免于自氧化。
