Fig. 1. (a) A single photocatalyst where photogenerated electrons (e-) and holes (h+) recombine due to Coulomb attraction. (b) Type-II heterojunction, where electrons transfer from P2 to P1, while holes move from P1 to P2. (c) Liquid-phase Z-scheme, where electrons from P1 transfer to the VB of P2 via electron donors (D) and acceptors (A). (d) All-solid-state Z-scheme, where electrons from P1 transfer to the VB of P2 through conductive materials (e.g., Au). (e) Direct Z-scheme, where electrons from P1 recombine with holes from P2. (f) S-scheme, where band bending, an internal field, and Coulomb repulsion drive electron transfer from P1 to P2 and hole transfer from P2 to P1, with interfacial recombination. Adapted with permission from Zhang et al. [2] Copyright 2025 Nature Publishing Group.