Aligning potential differences within carbon nitride based photocatalysis for efficient solar energy harvesting

Highlights: • Intralayer potential difference (IPD) and band PD (BPD) within carbon nitride based photocatalysis were both engineered. • The individual contribution of IPD and BPD to governing the charge carriers was clearly illustrated. • The interaction between IPD and BPD on the throughput of different photocatalytic systems was unveiled. • Enhancement from PDs alignment was higher than that via modifications of other physiochemical properties of catalyst. Photocatalysis is essentially triggered by the photoinduced charge carriers, which are then oriented for the targeted redox reactions. However, the effects of intrinsic driving forces on charge carriers and their resulting photocatalytic throughputs remain unclear. Herein, we focus on two main potential differences (PDs), e.g., intralayer PD (IPD) within two-dimensional carbon nitride hybrids, and band PD (BPD) between the band positions of a semiconductor and the redox potentials of reactants that can actuate charge carriers for photocatalysis. In situ experiments and theoretical computations identify and differentiate the roles of the two PDs on the separation, transportation and catalytic utilization of charge carriers. It is noteworthy that the enhancement from PDs alignment in this work is higher than other physiochemical modifications (e.g., mass transfer and polymerization degree) for photocatalysis. This study may offer a guiding principle for aligning a photocatalyst with target reactions for energy conversion and chemical synthesis.