Bai Haoyuan, Lam Shiu Hei, Yang Jianhua, Cheng Xizhe, Li Shasha, Jiang Ruibin, Shao Lei, Wang Jianfang
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Adv Mater. 2022 Jan;34(2):e2104226. doi: 10.1002/adma.202104226. Epub 2021 Oct 29.
Plasmonic photocatalysis has received much attention owing to attractive plasmonic enhancement effects in improving the solar-to-chemical conversion efficiency. However, the photocatalytic efficiencies have remained low mainly due to the short carrier lifetime caused by the rapid recombination of plasmon-generated hot charge carriers. Although plasmonic metal-semiconductor heterostructures can improve the separation of hot charge carriers, a large portion of the hot charge carriers are lost when they cross the Schottky barrier. Herein, a Schottky-barrier-free plasmonic semiconductor photocatalyst, MoO , which allows for efficient N photofixation in a "one-stone-two-birds" manner, is demonstrated. The oxygen vacancies in MoO serve as the "stone." They "kill two birds" by functioning as the active sites for the chemisorption of N molecules and inducing localized surface plasmon resonance for the generation of hot charge carriers. Benefiting from this unique strategy, plasmonic MoO exhibits a remarkable photoreactivity for NH production up to the wavelength of 1064 nm with apparent quantum efficiencies over 1%, and a solar-to-ammonia conversion efficiency of 0.057% without any hole scavenger. This work shows the great potential of plasmonic semiconductors to be directly used for photocatalysis. The concept of the Schottky-barrier-free design will pave a new path for the rational design of efficient photocatalysts.
由于在提高太阳能到化学能转换效率方面具有引人注目的等离子体增强效应，等离子体光催化受到了广泛关注。然而，光催化效率一直较低，主要原因是等离子体产生的热载流子快速复合导致载流子寿命较短。尽管等离子体金属-半导体异质结构可以改善热载流子的分离，但很大一部分热载流子在穿过肖特基势垒时会损失。在此，展示了一种无肖特基势垒的等离子体半导体光催化剂MoO ，它能够以“一石二鸟”的方式实现高效的N光固定。MoO 中的氧空位充当“石头”。它们通过作为N分子化学吸附的活性位点以及诱导局部表面等离子体共振以产生热载流子来“一石二鸟”。受益于这种独特策略，等离子体MoO 对高达1064 nm波长的NH 生成表现出显著的光反应性，表观量子效率超过1%，并且在没有任何空穴清除剂的情况下太阳能到氨的转换效率为0.057%。这项工作展示了等离子体半导体直接用于光催化的巨大潜力。无肖特基势垒设计的概念将为高效光催化剂的合理设计开辟一条新途径。
