Introducing Hydrogen-Bonding Microenvironment in Close Proximity to Single-Atom Sites for Boosting Photocatalytic Hydrogen Production
Shuaishuai Hu, Ming‐Liang Gao, Jiajia Huang, He Wang, Qingyu Wang, Weijie Yang, Zhihu Sun, Xusheng Zheng, Hai‐Long Jiang
Abstract
Inspired by enzymatic catalysis, it is crucial to construct hydrogen-bonding-rich microenvironment around catalytic sites; unfortunately, its precise construction and understanding how the distance between such microenvironment and catalytic sites affects the catalysis remain significantly challenging. In this work, a series of metal–organic framework (MOF)-based single-atom Ru 1 catalysts, namely, Ru 1 /UiO-67-X (X = -H, - m -(NH 2 ) 2, - o -(NH 2 ) 2 ), have been synthesized, where the distance between the hydrogen-bonding microenvironment and Ru 1 sites is modulated by altering the location of amino groups. The −NH 2 group can form hydrogen bonds with H 2 O, constituting a unique microenvironment that causes an increased water concentration around the Ru 1 sites. Remarkably, Ru 1 /UiO-67- o -(NH 2 ) 2 displays a superior photocatalytic hydrogen production rate, ∼4.6 and ∼146.6 times of Ru 1 /UiO-67- m -(NH 2 ) 2 and Ru 1 /UiO-67, respectively. Both experimental and computational results suggest that the close proximity of amino groups to the Ru 1 sites in Ru 1 /UiO-67- o -(NH 2 ) 2 improves charge transfer and H 2 O dissociation, accounting for the promoted photocatalytic hydrogen production.