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

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