Powering portables with sunlight and H2O/O2-mediators: a self-biased photoelectrochemical system via Cu-based sulfide nanocages and an engineered BiVO4 photoanode.

The metal-sulfurization strategy steers the 4e- O2 reduction pathway of a porous electrocatalyst. Integrated with a well-developed quasi-solid-state electrolyte and a FeNiOOH/FeN-BiVO4 photoanode, this self-biased portable photoelectrochemical (PEC) cell generates electricity via H2O/O2 mediators, exhibiting robust durability and wide-temperature tolerance.