Reversible bismuth reduction-driven dark photoelectrochemistry

| ) signal under air conditions. Significantly, owing to the selective binding and charge transfer between glutathione and BiOBr, the reversibility of bismuth reduction is increased, with a 10-fold enhancement of reverse photocurrent. Compared to traditional PEC systems, the dark-PEC system enables the selective recognition of reductant molecules by photocathodes, unveiling an original PEC reaction mechanism. This study will offer valuable insights into device design and redox processes in the PEC field.