Oxidation-Enhanced Piezocatalytic Activity in Carbon Nitride-Based Catalysts for Hydrogen and Hydrogen Peroxide Production.

Driven by the urgent need for a green, safe, and cost-effective approach to producing H and HO-both highly valuable in green energy and environmental protection fields-piezocatalysis, which converts mechanical energy into valuable chemicals, has emerged as a promising solution. However, current catalyst systems face challenges due to the need for materials with both a strong piezoelectric effect and favorable catalytic activity. Herein, the construction of an oxidized carbon nitride (g-CN) matrix anchored with TiO nanoparticles via alkaline hydrothermal treatment is reported. Under ultrasonication, the g-CN/TiO composite exhibits optimal performance under carefully controlled alkaline hydrothermal conditions. With a low concentration of Ba(OH) during hydrothermal treatment, Ba(OH) provides an alkaline medium, oxidizing the g-CN species and introducing structural defects into the g-CN framework. The disruption of the g-CN matrix, along with its interaction with TiO nanoparticles, enhances the piezoelectric effect. Consequently, the oxidized g-CN/TiO composite achieves a remarkable H production rate of 4427.2 μmol g and an HO production rate of 809.3 μmol g within 1 h without the addition of any sacrificial agents or cocatalysts. This work presents an effective strategy for the structural optimization of g-CN-based materials and may inspire new approaches for designing advanced piezocatalysts.