Modification of tantalum nitride (Ta(3)N(5)), which has a band gap of 2.1 eV, with nanoparticulate iridium (Ir) and rutile titania (R-TiO(2)) achieved functionality as an O(2) evolution photocatalyst in a two-step water-splitting system with an IO(3)(-)/I(-) shuttle redox mediator under visible light (lambda > 420 nm) in combination with a Pt/ZrO(2)/TaON H(2) evolution photocatalyst. The loaded Ir nanoparticles acted as active sites to reduce IO(3)(-) to I(-), while the R-TiO(2) modifier suppressed the adsorption of I(-) on Ta(3)N(5), allowing Ta(3)N(5) to evolve O(2) in the two-step water-splitting system.

A composite material consisting of tantalum oxynitride (TaON) and monoclinic zirconium oxide (m-ZrO 2 ) is prepared by a surface modification method as a photocatalyst with enhanced activity for H 2 evolution from water under visible light ( > 420 nm). The composite is prepared by loading particulate Ta 2 O 5 with nanoparticulate m-ZrO 2 followed by nitridation at 1123 K for 15 h under NH 3 flow. The activity of the m-ZrO 2 /TaON composite for H 2 evolution from aqueous methanol solution is higher than that of either m-ZrO 2 or TaON when loaded with nanoparticulate ruthenium as a H 2 evolution site. The highest activity is obtained using a composite prepared with a Zr/Ta molar ratio of 0.1. The optimized material also provides elevated activity when used as an H 2 evolution photocatalyst in Z-scheme overall water splitting in combination with Pt-loaded WO 3 as an O 2 evolution photocatalyst and an IO 3 À /I À shuttle redox mediator. The improvement in activity is attributed to the suppression of surface defect formation by inhibiting tantalum reduction during nitridation.

Tantalum nitride (Ta3N5) modified with various O2-evolution cocatalysts was employed as a photocatalyst for water oxidation under visible light (λ>420 nm) in an attempt to construct a redox-mediator-free Z-scheme water-splitting system. Ta3N5 was prepared by nitriding Ta2O5 powder under a flow of NH3 at 1023-1223 K. The activity of Ta3N5 for water oxidation from an aqueous AgNO3 solution as an electron acceptor without cocatalyst was dependent on the generation of a well-crystallized Ta3N5 phase with a low density of anionic defects. Modification of Ta3N5 with nanoparticulate metal oxides as cocatalysts for O2 evolution improved water-oxidation activity. Of the cocatalysts examined, cobalt oxide (CoO(x)) was found to be the most effective, improving the water-oxidation efficiency of Ta3N5 by six to seven times. Further modification of CoO(x)/Ta3N5 with metallic Ir as an electron sink allowed one to achieve Z-scheme water splitting under simulated sunlight through interparticle electron transfer without the need for a shuttle redox mediator in combination with Ru-loaded SrTiO3 doped with Rh as a H2-evolution photocatalyst.

The effects of organizational justice on psychological distress seem to be mediated by reward at work (or ERI) while those regarding work engagement may be mediated by worksite support to a large extent, at least in Japanese workers.

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