Dopamine Modified g‑C₃N₄ and Its Enhanced Visible-Light Photocatalytic H₂‑Production\nActivity

Abstract

Photocatalytic\nwater splitting is a promising strategy to convert\nsolar energy into chemical energy. Herein, a series of g-C₃N₄/polydopamine (g-C₃N₄/PDA) composites\nwere successfully fabricated by in situ polymerization of dopamine\non the g-C₃N₄ surface. Among all the as-prepared\ncomposites, the best photocatalytic hydrogen evolution rate of the\nas-prepared composites was up to 69 μmol h^–1 under the irradiation of visible light (λ > 420 nm), which\nwas about 4.5 times than that of pristine g-C₃N₄ (16 μmol h^–1). The enhancement of photocatalytic\nH₂ evolution is reasonably attributed to the markedly enhanced\nlight harvesting, broadened spectral response range and low onset\npotential of H₂ production, as well as effective separation\nand rapid transportation of photogenerated charge carriers. More importantly,\nthe surface modification of g-C₃N₄ by a small\namount of PDA can effectively inhibit the overgrowth of Pt nanoparticles\n(NPs) during the photocatalytic reactions, which promotes the photoelectron\ninjection and better photocatalytic activity. This work should provide\na new insight into preparing metal-free polymer–polymer composites\nwith effective solar energy conversion.