Photoelectrochemical Catalysis of Waste Polyethylene Terephthalate Plastic to Coproduce Formic Acid and Hydrogen

A novel strategy for modulating the oxidation ability of the Fe2O3/Ni(OH)x photoanode's photogenerated holes was successfully introduced to realize the photoelectrochemical (PEC) catalysis of waste polyethylene terephthalate (PET) plastic for the first time. This PEC process achieved an up to ∼100% Faradaic efficiency of formic acid/formate. The underlying Ni2+/Ni3+ redox couple-mediated mechanism was explored, which suggested that the introduction of the Ni(OH)x cocatalyst can effectively tune the oxidation ability of the photogenerated holes to improve the selectivity toward the desired formic acid/formate products.