Triazinyl-graphdiyne induces electron directional migration to drive charge separation of CdS for photocatalytic hydrogen evolution

Abstract

Solar photocatalytic hydrogen generation is crucial for addressing energy and environmental challenges. The high recombination rate and limited redox capability of photocatalysts hamper the broad utilization of photocatalytic water splitting for hydrogen generation, necessitating the development of efficient co-catalysts for effective separation of photo-generated electron–hole pairs. In this work, a strategy was developed for the rapid preparation of triazine-graphdiyne (TA-GDY) using mechanical ball milling and its complexation with CdS, with a hydrogen production activity as high as 62.48 mmol g⁻¹. The experimental results demonstrate that TA-GDY not only enhances the carrier separation efficiency, but more importantly, the nitrogen atoms and the alkyne bonds collectively facilitate electron migration, leading to the formation of a centre for aggregating photogenerated electrons. This provides an adsorption-reduced active site for efficient H₂ production and exhibits a strong H⁺ trapping ability. Moreover, the construction of Schottky heterojunctions in photocatalytic hydrogen production was corroborated by in situ XPS and theoretical calculations. This work presents a viable approach for the design and induction of electron-directed migration of novel graphdiyne in heterojunction photocatalysts.