Highly Efficient Visible-Light-Driven Photocatalytic H_2 Production Using Carbon Particle/g-C_3N_4 Photocatalysts with An Electron Donor

摘要

Recently, graphitic carbon nitride (g-CN) has attracted attention as a promising hydrogen production substance. However, the photocatalytic activity of g-CN is limited by the high recombination rate of its photogenerated charge carriers. Therefore, effective electron-hole separation is an important factor for enhancing photocatalytic performance. Herein, novel carbon particles/g-CN composite photocatalysts (C/Tg-CN) were prepared by a facile two-step calcination using carbon particles and melamine as starting materials. The photocatalytic activity of the synthesized samples was evaluated for photocatalytic hydrogen production with an electron donor under visible irradiation (λ ≥ 420 nm). Consequently, the highest photocatalytic hydrogen evolution rate for 0.5 wt.% C/Tg-CN was approximately 340 μmol/g h, about 43 times higher than that of pure g-CN. This improved photocatalytic activity was attributed to carbon particles acting as electron reservoirs, which trap electrons to promote charge separation, and light harvesters, which enhance visible-light absorption.