Gd₂Ti₂O₇/In₂O₃: Efficient Visible‐Light‐Driven Heterojunction‐Based Composite Photocatalysts for Hydrogen Production

Abstract

Abstract A series of Gd 2 Ti 2 O 7 /In 2 O 3 heterojunction‐based composite photocatalysts was prepared by using solid‐state reaction methods and their activity was evaluated by measuring the photocatalytic H 2 production under visible light ( λ ≥400 nm). The materials were characterised by using XRD, diffuse reflectance UV (DRUV)/Vis spectroscopy, TEM, field emission SEM (FESEM), photoluminescence (PL) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and BET surface area and photocurrent measurements. The modification of Gd 2 Ti 2 O 7 with In 2 O 3 resulted in a remarkable enhancement of the activity for H 2 production with respect to the single components under visible light. The photocurrent and Mulliken electronegativity results show that Gd 2 Ti 2 O 7 and In 2 O 3 have a well‐matched band potential to exhibit synergic effects. The enhanced activity may be ascribed to the light absorption properties and the reduction of the recombination of charge carriers at the composite interface. The catalyst Gd 2 Ti 2 O 7 /In 2 O 3 with 60 at % In (60 IGTO) showed the highest activity in comparison to the other composite materials prepared.