Activating d10 electronic configuration to regulate p-band centers as efficient active sites for solar energy conversion into H2 by surface atomic arrangement

Abstract

Relationship between the activity for photocatalytic H₂O overall splitting (HOS) and the electron occupancy on d orbits of the active component in photocatalysts shows volcanic diagram, and specially the d¹⁰ electronic configuration in valley bottom exhibits inert activity, which seriously fetters the development of catalytic materials with great potentials. Herein, In d¹⁰ electronic configuration of In₂O₃ was activated by phosphorus atoms replacing its lattice oxygen to regulate the collocation of the ascended In 5p-band (In ɛ_5p) and descended O 2p-band (O ɛ_2p) centers as efficient active sites for chemisorption to *OH and *H during forward HOS, respectively, along with a declined In 4d-band center (In ɛ_4d) to inhibit its backward reaction. A stable STH efficiency of 2.23% under AM 1.5 G irradiation at 65 °C has been obtained over the activated d¹⁰ electronic configuration with a lowered activation energy for H₂ evolution, verified by femtosecond transient absorption spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations of dynamics. These findings devote to activating d¹⁰ electronic configuration for resolving the reaction energy barrier and dynamical bottleneck of forward HOS, which expands the exploration of high-efficiency catalytic materials.