Synthesis and Doping Strategies to Improve the Photoelectrochemical Water Oxidation Activity of BiVO4 Photoanodes

Abstract

Abstract BiVO4 is one of the most investigated and most promising metal oxide based photoanode materials for photoelectrochemical (PEC) water oxidation. Although it has several advantages (suitable band gap around 2.4 eV, suitable valence-band position for water oxidation, low toxicity, high abundance), it suffers from slow charge-carrier transport properties, high surface recombination, and limited water-oxidation activity. In the present work, we review the synthesis and doping strategies that we developed in the last years to improve the PEC performance of BiVO4 photoanodes. Strategies ranging from single anion doping or cation doping to anion and cation co-doping will be presented for fluoride and molybdenum as anion and cation dopants, respectively. One major result is that co-doping allows combining the most important PEC specific benefits of each type of dopant, i.e. an increased charge-injection efficiency in case of fluoride as well as an increased charge-separation efficiency in case of molybdenum.