Graphite-like carbon nitride (C3N4) modified N-doped LaTiO3 nanocomposite for higher visible light photocatalytic and photo-electrochemical performance

A novel g-C3N4/N doped-LaTiO3 organic-inorganic hybrid (CLT) is synthesized via a sol-gel polymerized complex method followed by a facile solid state transformation route. The as synthesized hybrid is characterized using powder X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The results show that the band gap of LaTiO3 is narrowed and also could absorb visible light after doping of N into the LaTiO3 lattice. It is observed that N-doped LaTiO3 nanoparticles are wrapped with the g-C3N4 nano-sheet layers, forming a heterojunction structure, in the CLT hybrid. The CLT hybrid exhibits not only longer wavelength absorption in the visible region but also an enhancement in the photocatalytic and photocurrent activity under visible light compared to pure N-doped LaTiO3 and g-C3N4. Moreover, the hybrid is photo-stable and reusable. The improved visible light photocatalytic activity of the CLT hybrid is ascribed to its suitable band edge potential, better separation of photoinduced charge carriers owing to the heterojunction, and the synergistic effect of g-C3N4 and N-LaTiO3. Based on the results of photoluminescence, electrochemical impedance, and radical scavenger studies, a possible photocatalytic mechanism for the hybrid is also proposed. The g-C3N4/N-LaTiO3 hetero-structure is expected to provide new insight for the application of rare-earth-metal based perovskite oxides in environmental remediation and could be suitable for water splitting and other energy related applications as well. (C) 2018 Elsevier B.V. All rights reserved.