Aldehyde-modified C3N4 boosts solution plasma catalysis for H2O2 production

Solution plasma catalysis has emerged as a promising strategy for the sustainable and rapid production of hydrogen peroxide (H 2 O 2 ) from water and oxygen by clean electricity. However, the uncontrollable electron loss and inefficient utilization of reactive species in solution plasma significantly limit the plasma-to-H 2 O 2 (PTH) conversion efficiency. This lack of control over the plasma environment makes it challenging to design catalysts capable of selectively channeling reactive species toward H 2 O 2 production. Here, we develop modified C 3 N 4 with different functional groups to improve PTH conversion efficiency. The aldehyde-modified C 3 N 4 achieves an unprecedented H 2 O 2 production rate of 4.4 ± 0.1 mM h −1 and a remarkable PTH conversion efficiency of 1.3 %, which is 16 times higher than that of the plasma system without a catalyst. We clarified by density functional calculations and spectroscopic measurements that the improved H 2 O 2 yields and efficiency are due to the modification of the electron-withdrawing groups to promote the generation of 1 O 2 intermediates. This work confirms the critical importance of rational catalyst design to improve PTH conversion efficiency, paving the way for sustainable and rapid solution-based chemical synthesis.