Solvothermal fusion of Ag‐ and N‐doped LiTaO3 perovskite nanospheres for improved photocatalytic hydrogen production

Abstract

Tantalate semiconductor photocatalyst has received significant attention as an alternative promising material to mitigate the globally increasing energy demand with the course of action of the produced hydrogen. In this report, an efficient enhancement in the hydrogen production under ultraviolet (UV) light by Ag‐ and N‐doped LiTaO3 via solvothermal strategy is proposed. The structural appearance and the spherical morphology are affirmed from the X‐ray diffraction and field emission scanning electron microscopy (FESEM) analysis. The bandgap of the prepared photocatalysts is calculated as 5.12, 4.92, and 4.82 eV for undoped LiTaO3, Ag, and N‐doped LiTaO3 nanoparticles using Tauc's plot. Moreover, the band position of the synthesized LiTaO3 and also with its dopants is calculated by the Mulliken electro negativity method. The elemental composition of the synthesized photocatalyst is confirmed from the energy dispersive analysis (EDS). Photocatalytic water splitting results over Ag‐ and N‐doped LiTaO3 photocatalyst showed that the rate of H2 evolution from formic acid aqueous solution was 240 and 123 μmolh−1 with an apparent quantum yield of 3.11% and 1.59%, whereas for undoped LiTaO3, the rate is quite lower to be 71 μmolh−1. The reason behind the high catalytic activity of Ag‐doped LiTaO3 is explained by the fact that the higher electronegativity of Ag (1.93) as compared with Ta (1.5) resulted in quite transfer of photoexcited electrons from the conduction band of LiTaO3 to the Ag species. Interestingly, up to the best of our knowledge, this is the first study regarding the photocatalytic hydrogen evolution for Ag‐ and N‐doped LiTaO3.