Unbiased Stable Photoelectrochemical Glycerol Oxidation on Hematite Photoanodes
Kerong Su, Hengyi Chen, Shijie Ren, Rui‐Ting Gao, Limin Wu, Lei Wang
Abstract
Abstract Photoelectrochemical glycerol oxidation reaction (PEC GOR) is considered as one of the promising strategies for obtaining high‐value products and transforming solar energy to hydrogen. Herein, we report that a Ge/Zr co‐doped Fe 2 O 3 photoanode present an excellent and stable PEC performance for glycerol oxidation to formate (FA) product. The Ge and Zr co‐doping synergistically reduce charge carrier recombination and enhance charge transfer kinetics of the photoanode, promoting the selectivity and Faradaic efficiency toward FA chemical. Further the deposition of NiFeB co‐catalyst promotes the cleavage of C─C bonds in glycerol molecules while inhibiting oxygen evolution reaction and facilitating FA accumulation. Impressively, the unbiased PEC tandem configuration for glycerol oxidation was established for coupling NiFeB/Ge/Zr‐Fe 2 O 3 photoanode with Fe(Pt)‐NC cathode, achieving a photocurrent density of ∼1.9 mA cm −2 with continuously operation of 100 h. The bias‐free device maintains FA selectivity of above 80% with an accumulation of 1683 µmol cm −2 , representing the best PEC GOR performance toward high‐value chemicals reported so far. The reaction mechanism was clarified through in situ characterization. This work provides new avenues for the sustainable solar‐powered chemical synthesis of unbiased PEC systems with high selectivity and durability.