Efficient Photocatalytic Water Splitting Using Al-Doped SrTiO₃ Coloaded with Molybdenum Oxide and Rhodium–Chromium Oxide

Abstract

Al-doped SrTiO3 loaded with a rhodium–chromium mixed oxide (RhCrO x /STO:Al) efficiently promotes photocatalytic overall water splitting with an apparent quantum yield (AQY) of 56% under 365 nm ultraviolet (UV) light. Further increasing this AQY is of vital importance, because this value determines the maximum solar to hydrogen energy conversion efficiency that can be achieved. Herein, we demonstrate that the AQY during overall water splitting by RhCrO x /STO:Al is improved by 20% (to 69% at 365 nm) by coloading of molybdenum oxide (MoO y , 0.03 wt % as Mo) followed by calcination. Reductively photodeposited MoO y modifies the chemical state of the RhCrO x cocatalyst and likely promotes photocatalytic H2 evolution, whereas MoO y loaded onto STO:Al does not catalyze either photocatalytic H2 or O2 evolution. The present study indicates a means of further enhancing the water-splitting activity of highly efficient cocatalyst/photocatalyst composites by loading small amounts of promoters in a facile manner.

Hydrothermal synthesis of single-crystal Cr-doped SrTiO3 for efficient visible-light responsive photocatalytic hydrogen evolution

“…Therefore, modifications to SrTiO 3 are widely attempted to narrow the band-gap and thus enlarge its light-harvesting region. Chemical substitutional doping has been proposed as an effective method to modify SrTiO 3 [6], in order to obtain promoted photocatalytic activities, such as F-doped SrTiO 3 [7], Eu-doped SrTiO 3 [8], Al-doped SrTiO 3 [9], Cr-doped SrTiO 3 [10]. Among the abundant doped SrTiO 3 materials, Cr-doped SrTiO 3 exhibits variable properties caused by the suitable ionic radius of Cr 3+ (0.615 Å), which lies between those of Sr 2+ (1.18 Å) and Ti 4+ (0.605 Å) ions [11,12].…”

Achievement of High Photocatalytic Performance to BaTi4O9 Toward Overall H2O Splitting

“…The result suggests that the degradation of the Rh 0.7 Cr 1.3 O 3 co‐catalyst is also progress beside the overall H 2 O splitting. According to the previous studies, the degradation of the Rh y Cr 2‐y O 3 co‐catalyst was reported to proceed by oxidizing Cr 3+ to Cr 6+ as chromate ion to dissolve in H 2 O. From the investigations in the previous study, under the oxidation process of H 2 O by photo‐generated holes, the degradation of the Rh 0.7 Cr 1.3 O 3 co‐catalyst also proceeds instead of production of O 2 .…”

“…Recently, metal ion doped SrTiO 3 combined with a Rh y Cr 2‐y O 3 co‐catalyst was reported to show the excellent photocatalytic activity to the reaction. Particularly, Al ion doped SrTiO 3 prepared by the flux method exhibits extremely high photocatalytic activity under the irradiation of near‐UV region light that is containing the solar irradiation, where the apparent quantum yield is more than 50 % at 365 nm. A panel type reactor was made with using the photocatalyst and the overall H 2 O splitting was demonstrated under solar irradiation .…”

“…A panel type reactor was made with using the photocatalyst and the overall H 2 O splitting was demonstrated under solar irradiation . Moreover, the photocatalyst has been reported to improve the photocatalytic activity and the durability to overall H 2 O splitting . Besides SrTiO 3 , few investigations have been carried out on the photocatalysts of Ti mixed oxides that can work under near UV irradiation for improving the photocatalytic activity to the level for the practical application as Al doped SrTiO 3 .…”

In‐Situ Annealing of the (110) and (001) Surfaces of SrTiO3 Nanocuboids by High‐Resolution Transmission Electron Microscopy

“…In this work we report on the thermal annealing of SrTiO 3 (STO) nanocuboids, exhibiting highly ordered {110} and {001} facets. STO is an important material that can act as a substrate for the growth of high‐temperature superconducting thin films and plays a major role as a catalyst support and in photocatalysis . Understanding surface modifications of STO with temperature at the nanoscale is therefore extremely valuable to a wide range of industrial applications.…”