Compositional Screening of the Pb–Bi–Mo–O System. Spontaneous Formation of a Composite of p-PbMoO₄ and n-Bi₂O₃ with Improved Photoelectrochemical Efficiency and Stability

Abstract

Scanning electrochemical microscopy (SECM) was used to identify more efficient p-type photocatalysts for H+ reduction in the Pb–Bi–Mo trimetal oxide system. An atomic ratio of (1:1:1) between Pb, Bi, and Mo showed higher photocurrent than other spots in screening experiments. The crystal structure of Pb–Bi–Mo oxide was studied by X-ray diffraction, indicating that a composite of p-PbMoO4 and n-Bi2O3 coexisted as a heterostructure. Photoelectrochemical performance of the p-PbMoO4/n-Bi2O3 composite electrode showed enhanced stability for the H+ and O2 reduction reactions. We propose a reaction mechanism to explain this stabilization of a p-type semiconductor.

In Situ Analytical Techniques for the Investigation of Material Stability and Interface Dynamics in Electrocatalytic and Photoelectrochemical Applications

“…[ 231 ] The Bard group has reported many studies of spatially resolved photoelectrode activity enabled by light‐coupled SECM. [ 232–240 ] They have pioneered the application of SECM as a screening technique for photoelectrocatalysts by imaging the illuminated activity of arrays of compositionally varied catalyst spots on a semiconductor [ 232 ] or varied doping of a photoelectrode (Figure 12f). [ 233 ] In another novel photoelectrochemistry application, Esposito et al.…”

Spray Pyrolysis as a Combinatorial Method for the Generation of Photocatalyst Libraries

“…The most common method of synthesizing libraries of materials is by inkjet printing or jet dispensing of either aqueous metal ion solutions (usually as the nitrate and sometimes acidified) or metal salts dissolved in more viscous solvents, such as ethylene glycol, − 3:1 water/glycerol, water/∼30% diethylene glycol or ∼30% diethylene glycol with 1% diethylene glycol monobutyl ether. , Higher viscosities serve to control the spread of material on the substrate. The Sayama group used butyl acetate with 0.2 M ethyl cellulose (to increase viscosity) to dissolve the metal salts and then mixed combinations of the different metal precursor solutions prior to printing. , This addresses the concern with printing individual solutions over one another that they may not be completely mixed to yield a homogeneous solution before being oxidized .…”

Effective Formation of WO3 Nanoparticle/Bi2S3 Nanowire Composite for Improved Photoelectrochemical Performance

“…Several strategies have recently been developed to improve PEC performance, such as morphology modification, electrocatalyst loading, and proper doping on semiconductor . Furthermore, heterostructures, in which two semiconductor materials are connected in series using currently available semiconductors, such as WO 3 /BiVO 4 , WO 3 /Fe 2 O 3 , WO 3 /CuWO 4 , TiO 2 /CdS/Bi 2 S 3 , CaFe 2 O 4 /TaON, WO 3 /ZnWO 4 , Cu 2 O/TiO 2 , PbMoO 4 /Bi 2 O 3 , n-Si/n-TiO 2 , and CuFeO 2 /CuO, have been extensively studied as promising photoelectrodes. In these heterostructures, the semiconductor can promote conversion efficiency through enhanced light absorption and charge separation.…”