Pre‐Coordination Induced Further Deamination to Create Inter‐Chain Cross‐Linking in Carbon Nitride for Enhanced Photocatalytic H2O2 Production

Abstract

AbstractCreating cross‐linking to establish efficient inter‐chain charge‐transfer channels in carbon nitride represents a promising strategy for enhancing its photocatalytic capabilities. Molten salt‐assisted calcining has emerged as a method for preparing cross‐linked carbon nitrides. However, the precise influence of molten salts on the molecular structure of carbon nitride remains to be fully elucidated. Herein, we develop a KCl guided cross‐linking reaction to preliminarily reveal the formation mechanism of cross‐linking. The cross‐linking reaction is initiated by the pre‐coordination of amino groups with K+. Subsequent heating at high temperature converts the amino groups into chlorines. Then, dechlorination leads to the formation of cross‐linking. Thus, this cross‐linking reaction can be accurately described as a pre‐coordination‐induced, two‐step deamination reaction. The pre‐coordination step plays a pivotal role in the cross‐linking process. Sufficient pre‐coordination results in a relatively high cross‐linking degree of the as‐prepared CNK‐2. Consequently, CNK‐2 demonstrates a significantly enhanced photocatalytic H2O2 production, with a generation rate of 682 μmol L−1 h−1, about 59 times that of traditional carbon nitride.