Xiangjiu Guan

Continuous solid solutions of Na0.5La0.5TiO3–LaCrO3 for photocatalytic H2 evolution under visible-light irradiation

A series of continuous (Na0.5La0.5TiO3)1−x(LaCrO3)x solid solutions with orthorhombic-phase perovskite structure and with LaCrO3 contents (x) in the range from 0 to 1.0 were synthesized by a facile polymerized complex method, and were employed as photocatalysts for H2 evolution under visible-light irradiation. It was found that photocatalytic activities of the solid solutions significantly increased with the increase of x to 0.3, and reached the highest H2-evolution rate of 238.2 μmol h−1 gcat−1 on (Na0.5La0.5TiO3)0.7(LaCrO3)0.3, because the narrowed bandgaps of samples enhanced the generation of charge carriers and the increased lattice distortion of samples could promote the separation and migration of charge carriers. Nevertheless, photocatalytic activities of the solid solutions gradually decreased with the further increase of x from 0.3, since both the bandgaps and lattice distortion rarely changed but Cr6+ and defects gradually increased and thus accelerated the recombination of charge carriers.

W ion implantation boosting visible-light photoelectrochemical water splitting over ZnO nanorod arrays

Abstract. W ions were doped into ZnO nanorod arrays hydrothermally grown on the F-doped tin-oxide-coated glass substrates via an advanced ion implantation technique for photoelectrochemical (PEC) water splitting under visible light. It was found that W incorporation could narrow the bandgap of ZnO and shift the optical absorption into visible light regions obviously, with the one-dimensional nanorod structure maintained for superior charge transfer. As a result, the W-doped ZnO nanorod arrays exhibit considerable PEC performance relative to ZnO nanorod arrays under visible light illumination (λ>420  nm), with photocurrent density achieved up to 15.2  μA/cm2 at 1.0 V (versus Ag/AgCl). The obtained PEC properties indicate that ion implantation can be an alternative approach to develop unique materials for efficient solar energy conversion.