Activating molecular catalysts at the surface of metal oxides can be a promising strategy to overcome the sluggish interfacial kinetics and enhance the efficiencies for photo­(electro)­chemical (PEC) water oxidation. However, the physical association between inorganic semiconductors for PEC process and organometallic molecular catalysts for surface catalytic reactions generally remains a challenging problem. In the present work, Kläui-type organometallic precursor [Cp*Ir­{P­(O)­(OH)2}3]Na was first synthesized and subsequently successfully anchored onto BiVO4 nanopyramids grown on transparent conducting substrates through various procedures. Treating the resulting hybrid heteronanostructure with IO4 – induces a strong synergism between iridium atoms and BiVO4 nanocrystals that exhibits a 5.5 times enhancement in photocurrent density at 1.23 V vs reversible hydrogen electrode (RHE) for PEC water oxidation. This simple approach provides an effective alternative pathway for molecular catalysts anchoring on inorganic semiconductors for efficient renewable energy utilization.

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Nanoporous bismuth vanadate is modified simultaneously via tungsten doping and graphene surface modification for use as an efficient photoanode. The modified films were prepared on a FTO substrate by a drop-cast method followed by photoreduction of graphene oxide. SEM, XRD, Raman and XPS characterization was conducted to confirm the incorporation of tungsten and reduced graphene oxide (RGO), and to look into their influences on the structure and performance of BiVO. Electrochemical impedance spectroscopy analysis clearly revealed enhanced carrier density and improved electronic conductivity, which are beneficial for the enhancement of PEC performance in comparison to either individually doped or RGO modified BiVO. Our results indicated that the enhanced PEC performance can be attributed to the synergistic effect of bulk doping and surface modification that facilitates electron and hole transport and transfer in the bulk and at the semiconductor-electrolyte interface.

A series of tin(II)–antimonate photocatalysts with varied Sn content were prepared by altering the ion‐exchange time and reaction temperature to control their physicochemical properties, especially their band‐gaps and nanostructures. Furthermore, the effect of these catalysts on visible‐light‐driven photocatalytic H2‐evolution was also investigated. With an increase in Sn content, the narrowed band‐gaps enhanced the absorption of photons to excite the photogenerated charge carriers. A decrease in nanocrystal size approaching stoichiometric compositions impeded the recombination of the photogenerated charge carriers; the increased surface areas and pore volumes, owing to the nanostructural transformation, accelerated the redox reactions. Consequently, the photocatalytic activities gradually improved and the highest rate was observed for stoichiometric Sn2Sb2O7. As a result, the as‐prepared tin(II) antimonates—especially Sn2Sb2O7—were confirmed to be stable and efficient photocatalysts for visible‐light‐driven H2 evolution. Moreover, the activities of these photocatalysts could be improved by tuning their physicochemical properties to jointly optimize all of the processes in the photocatalytic reaction.