Mechanistic analysis of multiple processes controlling solar-driven H2O2 synthesis using engineered polymeric carbon nitride

Solar-driven hydrogen peroxide (H2O2) production presents unique merits of sustainability and environmental friendliness. Herein, efficient solar-driven H2O2 production through dioxygen reduction is achieved by employing polymeric carbon nitride framework with sodium cyanaminate moiety, affording a H2O2 production rate of 18.7 μmol h −1 mg−1 and an apparent quantum yield of 27.6% at 380 nm. The overall photocatalytic transformation process is systematically analyzed, and some previously unknown structural features and interactions are substantiated via experimental and theoretical methods. The structural features of cyanamino group and pyridinic nitrogen-coordinated soidum in the framework promote photon absorption, alter the energy landscape of the framework and improve charge separation efficiency, enhance surface adsorption of dioxygen, and create selective 2e− oxygen reduction reaction surface-active sites. Particularly, an electronic coupling interaction between O2 and surface, which boosts the population and prolongs the lifetime of the active shallow-trapped electrons, is experimentally substantiated.

Reduction of dioxygen to water by a Co(N2O2) complex with a 2,2′-bipyridine backbone

The first Co(N2O2)-based catalyst with intrinsic activity for dioxygen reduction to water instead of hydrogen peroxide is reported.

Introduction of Secondary Ligand in Titanium-Based Metal-Organic Frameworks for Visible-Light-Driven Photocatalytic Hydrogen Peroxide Production from Dioxygen Reduction

Introduction of multiple components with specific properties in metal–organic frameworks (MOFs) is an attractive strategy to modify their catalytic properties. Herein, through the introduction of ligand 4,4’,4’’,4’’’-(pyrene-1,3,6,8-tetrayl)tetrabenzoic acid (L2) in...

Identification and Analysis of Multiple Factors Controlling Solar-driven H2O2 Synthesis Using Engineered Polymeric Carbon Nitride

Solar-driven hydrogen peroxide (H2O2) production presents unique merits of sustainability and environmental friendliness. Herein, highly efficient solar-driven H2O2 production through dioxygen reduction is achieved by employing polymeric carbon nitride (PCN) framework with sodium cyanaminate moiety (PCN-NaCA), affording a superior H2O2 production rate of 175 μmol/h on 10 mg photocatalyst and a notable apparent quantum yield of 27.6% at 380 nm. The overall photocatalytic transformation process is systematically analyzed using various steady-state/transient spectroscopic and computational methods. The presence of sodium cyanaminate moiety in PCN-NaCA induces the following multiple effects: enhancing photon absorption, creating the coexistence of p-type and n-type domains, strengthening surface adsorption of dioxygen, and favoring highly selective 2e− ORR. In particular, the adsorption of dioxygen on PCN-NaCA enhances the population and lifetime of trapped electrons in the ps-ns time regime, which should have a notable synergic effect on oxygen reduction process.