Covalent Grafting of a Nickel Thiolate Catalyst onto Covalent Organic Frameworks for Increased Photocatalytic Activity
Jixian Wang, Lei Li, Shan Jiang, David James Young, Zhi‐Gang Ren, Hong‐Xi Li
Abstract
Abstract Covalent organic frameworks (COFs) have recently emerged as prospective photoactive materials with noble Pt as a cocatalyst for photocatalytic hydrogen evolution. In this work, a series of SH‐group‐functionalized covalent organic frameworks, TpPa‐1‐SH‐ X , is prepared by reaction of p ‐phenylenediamine (Pa) and 1,3,5‐triformylphloroglucinol (Tp) with p ‐NH 2 C 6 H 4 SH as a modulating agent. The reaction of TpPa‐1‐SH‐ X with Ni II acetylacetonate Ni(acac) 2 gave nickel thiolate‐immobilized TpPa‐1 (TpPa‐1‐SNi‐ X ). The highest hydrogen evolution rate was 10.87 mmol h −1 g −1 , which was an enhancement of 16.47, 3.83, and 1.84 times than that of the parent TpPa‐1, covalent‐bond‐free [( p ‐NH 2 C 6 H 4 S) 2 Ni] n /TpPa‐1‐SH‐10, and 3 wt % Pt‐deposited TpPa‐1, respectively. This enhanced photocatalytic hydrogen evolution is ascribed to enhanced crystallinity, the use of Ni II thiolate as a cocatalyst and covalent bonding between the cocatalyst and TpPa‐1.