Post-Calcined Carbon Nitride Nanosheets as an Efficient Photocatalyst for Hydrogen Production under Visible Light Irradiation

Abstract

Hydrogen production via photocatalytic water splitting using sunlight has enormous potential to solve the worldwide energy and environmental crisis. The key challenge in this process is to develop efficient photocatalysts which must satisfy several criteria such as strong sunlight absorption, effective charge separation, and high photochemical stability. Graphitic carbon nitride is one of the best semiconductors for hydrogen evolution because of its conduction band edge, narrow band gap, and high chemical stability. However, it produces a small amount of hydrogen under visible light irradiation due to its small surface area and high recombination rates. In this work, nanosheets of graphitic carbon nitride with carbon vacancies and nanoholes were synthesized by a two-step treatment process (argon treatment followed by air calcination). These post-calcined carbon nitride nanosheets exhibited much higher photocatalytic activity compared to common graphitic carbon nitride. By depositing platinum as a cocataly...