Formation and suppression of defects during heat treatment of BiVO₄ photoanodes for solar water splitting

Abstract

Heat treatment under different atmospheres influences defect formation and suppression in BiVO4, which significantly affect its carrier dynamics.

Efficient BiVO4 Photoanodes by Postsynthetic Treatment: Remarkable Improvements in Photoelectrochemical Performance from Facile Borate Modification

“…Them ost likely sites for the tetrahedral [B(OH) 4 ] À are the defects formed as ar esult of vanadium loss. [23,29] Thea dsorbed [B(OH) 4 ] À may act as ap assivator to reduce charge recombination [22a] and to facilitate extraction of holes to the surface. [30] More importantly,t he anchoring of the borate moiety at the catalytic active site significantly accelerated the catalytic rate of water oxidation.…”

Efficient BiVO4 Photoanodes by Postsynthetic Treatment: Remarkable Improvements in Photoelectrochemical Performance from Facile Borate Modification

“…Based on the control experiments, physical characterizations, and carrier transfer kinetics studies, we propose that the immersion treatment in borate buffer solution is indeed a spontaneous process in which the tetrahedral [B(OH) 4 ] − gradually interacts with the active site (that is, defect) on the BiVO 4 surface (Figure ). The most likely sites for the tetrahedral [B(OH) 4 ] − are the defects formed as a result of vanadium loss . The adsorbed [B(OH) 4 ] − may act as a passivator to reduce charge recombination and to facilitate extraction of holes to the surface .…”

The role of ultra-thin MnOx co-catalysts on the photoelectrochemical properties of BiVO4 photoanodes

“…BiVO 4 thin lms were deposited using spray pyrolysis. 23,[40][41][42] Commercial FTO-coated glass slides (uorine-doped tin dioxide, 15 U , À1 , TEC-15, Pilkington) were used as the substrates. Prior to the deposition, a three-step cleaning procedure of ultrasonication in 10 vol% Triton™ X-100 solution (Sigma Aldrich), acetone, and ethanol, each for 15 minutes, was followed.…”