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 2 and H 2 O 2 —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 ‐C 3 N 4 ) matrix anchored with TiO 2 nanoparticles via alkaline hydrothermal treatment is reported. Under ultrasonication, the g ‐C 3 N 4 /TiO 2 composite exhibits optimal performance under carefully controlled alkaline hydrothermal conditions. With a low concentration of Ba(OH) 2 during hydrothermal treatment, Ba(OH) 2 provides an alkaline medium, oxidizing the g ‐C 3 N 4 species and introducing structural defects into the g ‐C 3 N 4 framework. The disruption of the g ‐C 3 N 4 matrix, along with its interaction with TiO 2 nanoparticles, enhances the piezoelectric effect. Consequently, the oxidized g ‐C 3 N 4 /TiO 2 composite achieves a remarkable H 2 production rate of 4427.2 μmol g −1 and an H 2 O 2 production rate of 809.3 μmol g −1 within 1 h without the addition of any sacrificial agents or cocatalysts. This work presents an effective strategy for the structural optimization of g ‐C 3 N 4 ‐based materials and may inspire new approaches for designing advanced piezocatalysts.