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The photocatalytic conversion of CO2 using H2O over heterogeneous photocatalysts has attracted worldwide attention because it enables direct solar‐to‐chemical energy conversion. However, further development of this technology requires solutions to overcome the low formation rates of CO2 reduction products and their insufficient selectivity, mainly caused by the rapid charge recombination of photogenerated electron/hole pairs, competition for thermodynamically preferential H2 evolution from H2O, and the relatively low concentration of CO2 on the surface of the photocatalysts. Surface modification of heterogeneous photocatalysts is crucial for improving their formation rates and selectivity. This review article introduces four strategies for designing photocatalyst surfaces for the photocatalytic conversion of CO2 by H2O: (I) loading of an Ag cocatalyst, (II) utilisation of cocatalysts for H2O oxidation, (III) suppression of undesired H2 evolution, and (IV) loading of basic materials for CO2 adsorption. The strategies introduced in this review successfully enhanced the formation rates of the products and/or their selectivity in the heterogeneous photocatalytic conversion of CO2 by H2O. [ABSTRACT FROM AUTHOR]

Abstract: The photo‐electrochemical C−H bond activation of cyclohexane to produce cyclohexanol and cyclohexanone (KA oil) with high partial oxidation selectivity (99 %) and high current utilization ratio (76 %) was achieved in air at room temperature at atmospheric pressure. The production rate of KA oil was accelerated by applying a bias. The incident photon to current efficiencies at 365 and 420 nm were 57 % and 24 %, respectively. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) have been paid great attention in the field of the photocatalysis due to their interesting physicochemical properties such as positively charged hydroxide sheet, compositional flexibilities, and large surface area. We previously reported that the use of Ni–Al LDH as a photocatalyst enabled us to achieve the maximum conversion of CO 2 to CO with high selectivity among a series of synthesized LDHs, and chloride ions (Cl − ) in the reaction solution enhanced the amount of CO evolved. In this study, we attempted to prepare 16 different kinds of transition metal containing M 2+ –M 3+ LDHs (M 2+ = Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ ; M 3+ = V 3+ , Cr 3+ , Mn 3+ , and Fe 3+ ) and applied them to the photocatalytic conversion of CO 2 in an aqueous solution of NaCl. Ni–V LDH, which has large specific surface area, exhibited the highest activity for the CO evolution among these LDHs; however the formation of H 2 as a reduction product of protons (H + ) was totally suppressed. It is estimated that a combination of V 3+ and Cl − plays a significant role for the high photocatalytic activity and the high selectivity toward CO formation. [ABSTRACT FROM AUTHOR]