香港城市大学刘彬研究团队报道了原子分散的低价金促进光催化羟基自由基的产生。相关研究成果于2024年6月25日发表于国际一流学术期刊《自然—化学》。

提供负担得起的安全饮用水和普遍的卫生设施是一项重大的社会挑战。

该文中，研究人员开发了可以同时促进·OH和H₂O₂的光催化生成，在420nm处的表观量子效率超过85%的原子分散的Au-掺钾聚合氮化碳材料。将钾引入聚（庚嗪酰亚胺）基体中形成了强的K–N键，并使Au的氧化数接近0。广泛的实验表征和计算模拟表明，低价Au改变了材料的能带结构，以捕获在光激发下产生的高度局域化的空穴。

这些高度局部化的空穴可以促进1e^-水氧化反应，形成高度氧化的·OH，同时离解H₂O中的氢原子，这大大促进了氧还原为H₂O₂。光生·OH导致可见光响应超亲水性的效率提高。此外，现场固定床反应器中的光照可以以每天66L H₂Om^-2的速率对水进行消毒。

附：英文原文

Title: Atomically dispersed low-valent Au boosts photocatalytic hydroxyl radical production

Author: Teng, Zhenyuan, Yang, Hongbin, Zhang, Qitao, Cai, Wenan, Lu, Ying-Rui, Kato, Kosaku, Zhang, Zhenzong, Ding, Jie, Sun, Han, Liu, Sixiao, Wang, Chengyin, Chen, Peng, Yamakata, Akira, Chan, Ting-Shan, Su, Chenliang, Ohno, Teruhisa, Liu, Bin

Issue&Volume: 2024-06-25

Abstract: Providing affordable, safe drinking water and universal sanitation poses a grand societal challenge. Here we developed atomically dispersed Au on potassium-incorporated polymeric carbon nitride material that could simultaneously boost photocatalytic generation of ·OH and H2O2 with an apparent quantum efficiency over 85% at 420nm. Potassium introduction into the poly(heptazine imide) matrix formed strong K–N bonds and rendered Au with an oxidation number close to 0. Extensive experimental characterization and computational simulations revealed that the low-valent Au altered the materials’ band structure to trap highly localized holes produced under photoexcitation. These highly localized holes could boost the 1e water oxidation reaction to form highly oxidative ·OH and simultaneously dissociate the hydrogen atom in H2O, which greatly promoted the reduction of oxygen to H2O2. The photogenerated ·OH led to an efficiency enhancement for visible-light-response superhydrophilicity. Furthermore, photo-illumination in an onsite fixed-bed reactor could disinfect water at a rate of 66L H2Om2 per day.

DOI: 10.1038/s41557-024-01553-6

Source: https://www.nature.com/articles/s41557-024-01553-6