Accelerating the Hole Mobility of Graphitic Carbon Nitride for Photocatalytic Hydrogen Evolution via 2D/2D Heterojunction Structural Advantages and Ni(OH) 2 Characteristic

Although photocatalytic hydrogen evolution is significant for solar conversion and energy supply, the photocatalytic efficiency is hampered by the low photoinduced holes mobility. Herein, the 2D Ni(OH) 2 as an operational cocatalyst is integrated with 2D graphitic carbon nitride (2D‐CN) ultrafine to form a 2D/2D heterojunction to improve the photocatalytic hydrogen evolution. Due to the high mobility attribute of the Ni(OH) 2 holes and the unique 2D/2D heterojunction of Ni(OH) 2 /CN, the specific photocatalyst Ni(OH) 2 /2D‐CN accelerates the photocarrier separation/transport, thereby achieving the breakthrough of continuous photocatalytic hydrogen evolution without using Pt cocatalyst and sacrificial agent. Above all, the as‐obtained Ni(OH) 2 /2D‐CN exhibits a hydrogen evolution rate of 921.4 μmol h −1  g −1 with an external quantum efficiency of 5.21% at 400 nm using 10% triethanolamine as a sacrificial agent. The work provides a new research approach for the catalytic conversion of energy.