Facile “Spot‐Heating” Synthesis of Carbon Dots/Carbon Nitride for Solar Hydrogen Evolution Synchronously with Contaminant Decomposition

Abstract The use of solar energy to produce the clean hydrogen (H 2 ) energy from water splitting is a promising means of renewable energy conversion. High activation barriers for O 2 generation associated with the rate‐limiting steps require utilization of noble metal‐based cocatalysts, which complicates the fabrication procedure and compromises the stability of the catalyst. Here, a homogenous “spot heating” approach is designed via the ultrasonic cavitation effect for evenly embedding highly crystalline carbon quantum dots (CQDs) on 2D C 3 N 4 nanosheets. Based on density functional calculations and electrochemical experiments, the optimal introduction of CQDs into C 3 N 4 not only extends light absorption spectrum, but also reduces effective mass of electrons (e − ), facilitating photocarrier transport from excited sites. And, more importantly, the well‐organized CQDs with superior peroxidase mimetic activity can increase catalytic H 2 production through the process of (i) 2H 2 O → H 2 O 2 + H 2 ; (ii) H 2 O 2 →2 • OH; (iii) •OH + bisphenol A→ Final Products, with H 2 production rate (152 µmol g −1 h −1 ) several times higher than that for pure C 3 N 4 . This work demonstrates an ideal platform for efficient H 2 production with synergetic organic contaminant degradation, thereby opening possibilities for coupling energy conversion with environmental remediation.