harvesting and the quantum effi ciency for solar-driven water splitting, which is still the core mission for the scientifi c community on photocatalysis. The water splitting reaction into hydrogen and oxygen (2H 2 O → 2H 2 + O 2 , with change in Gibbs free energy Δr G 298 = +237.2 kJ mol −1) is composed of two half-reactions, namely, the oxygen evolution reaction (OER) via water oxidation (2H 2 O → O 2 + 4H + + 4e − , E 0 = +1.23 V vs. NHE) and the hydrogen evolution reaction (HER) via proton reduction (2H + + 2e − → H 2 , E 0 = 0 V vs. NHE). [ 2,9 ] The separation and transport of the photoexcited electrons and holes as well as the surface redox reactions on the photocatalysts are the key issues for photocatalytic water splitting into H 2 and O 2 .To address these issues, researchers have found that the loading of co-catalysts is an effective way to improve the overall reaction effi ciency. [9][10][11][12] These co-catalysts can create heterojunctions with the host photocatalyst to enhance charge separation, and meanwhile, serve as the active sites for the redox reactions (HER or OER) on the photocatalyst surface. Nevertheless, a single co-catalyst loading may only cause the unilateral migration of the charge carrier, either electrons or holes, which restricts the enhancement effect on the overall photocatalytic activity. Therefore, it is of great importance to achieve a dual co-catalyst loading with synergistic effects for simultaneously improving the HER and OER in order to attain a high effi ciency for the overall photocatalytic water splitting.Generally, noble metals, such as Pt, Au, and Pd, have been widely used as effective HER co-catalysts because of their the low overpotential. [ 10,13,14 ] The Schottky junctions formed at the metal-semiconductor interfaces can greatly promote the migration of photogenerated electrons from the semiconductor to the metal, which improves the charge separation and enhances hydrogen production via proton reduction on the metal surfaces. Recently, metallic Ru nanoparticles have received much attention as stable catalysts for effi cient hydrogen generation in a photocatalytic system thanks to their reduced cost. [ 15,16 ] As ruthenium oxide (RuO 2 ) is an effective OER catalyst that can accept photogenerated holes from excited photocatalysts, [ 12,[17][18][19][20][21] These two processes are involved in the overall water splitting. This work provides an important reference for designing highly effi cient photocatalysts for water splitting through loading of dual co-catalysts containing the same element but with different valence structures.

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Triangular Ag-Pd alloy nanoframes were successfully synthesized through galvanic replacement by using Ag nanoprisms as sacrificial templates. The ridge thickness of the Ag-Pd alloy nanoframes could be readily tuned by adjusting the amount of the Pd source during the reaction. These obtained triangular Ag-Pd alloy nanoframes exhibit superior electrocatalytic activity for the methanol oxidation reaction as compared with the commercial Pd/C catalyst due to the alloyed Ag-Pd composition as well as the hollow-framed structures. This work would be highly impactful in the rational design of future bimetallic alloy nanostructures with high catalytic activity for fuel cell systems.

Covalently grafting pyrene groups on polymeric carbon nitride enables photocatalytic CO2 reduction in aqueous solution with simultaneous alkene oxidation in organic phase.

Triangular AgAu@Pt nanoframes with a dendritic Pt shell were synthesized by employing Ag nanoprisms as sacrificial templates. Due to the unique frame-like nanostructure and ternary components, the AgAu@Pt nanoframes exhibit impressive electrocatalytic performance toward the methanol oxidation reaction with much higher activity, and better anti-poisoning capability than commercial Pt/C catalysts.