Covalent Grafting of a Nickel Thiolate Catalyst onto Covalent Organic Frameworks for Increased Photocatalytic Activity

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.