Oxide Defect Engineering Enables to Couple Solar Energy into Oxygen Activation

Abstract

Modern development of chemical manufacturing requires a substantial reduction in energy consumption and catalyst cost. Sunlight-driven chemical transformation by metal oxides holds great promise for this goal; however, it remains a grand challenge to efficiently couple solar energy into many catalytic reactions. Here we report that defect engineering on oxide catalyst can serve as a versatile approach to bridge light harvesting with surface reactions by ensuring species chemisorption. The chemisorption not only spatially enables the transfer of photoexcited electrons to reaction species, but also alters the form of active species to lower the photon energy requirement for reactions. In a proof of concept, oxygen molecules are activated into superoxide radicals on defect-rich tungsten oxide through visible-near-infrared illumination to trigger organic aerobic couplings of amines to corresponding imines. The excellent efficiency and durability for such a highly important process in chemical transformation can otherwise be virtually impossible to attain by counterpart materials.

Defective graphitic carbon nitride synthesized by controllable co-polymerization with enhanced visible light photocatalytic hydrogen evolution

“…As demonstrated in Figure 5, the signal at 2.003 can be assigned to an unpaired electron in π-conjugated aromatic rings of carbon nitride and electron trapped on defect. [44][45][46][47] With the increase of the capping ends from -H to -C 6 H 6 , the EPR intensity increases greatly. Particularly, CN-DPT exhibits the strongest signal, indicating that the charge carrier separation is optimized significantly, this is beneficial for delocalizing excitons, thus inhibits the annihilation during the photocatalysis.…”

Interfacial Defect Engineering for Improved Portable Zinc–Air Batteries with a Broad Working Temperature

“…As shown in Figure 1f,the increased intensity of peak Aand the slightly positive shift of peak Bsuggest the generation of more oxygen deficiencies [15] and charge transfer from the O1s core-state to the s, p,o rd hole-states of neighboring atoms [16] over the transition interfaces.T he higher photoluminescence (PL) spectra intensity [17] and enhanced electron spin resonance (ESR) signal [18] also suggest the many more oxygen deficiencies on the NiO/ CoO TINWs,t he number of deficiencies is demonstrated to be 2.02 times larger than that of NiCo 2 O 4 NWs by X-ray photoelectron spectroscopy (XPS) of O1s peak at 531.4 eV [19] ( Figure S6&Table S2). As shown in Figure 1f,the increased intensity of peak Aand the slightly positive shift of peak Bsuggest the generation of more oxygen deficiencies [15] and charge transfer from the O1s core-state to the s, p,o rd hole-states of neighboring atoms [16] over the transition interfaces.T he higher photoluminescence (PL) spectra intensity [17] and enhanced electron spin resonance (ESR) signal [18] also suggest the many more oxygen deficiencies on the NiO/ CoO TINWs,t he number of deficiencies is demonstrated to be 2.02 times larger than that of NiCo 2 O 4 NWs by X-ray photoelectron spectroscopy (XPS) of O1s peak at 531.4 eV [19] ( Figure S6&Table S2).…”

Recent progress on advanced design for photoelectrochemical reduction of CO2 to fuels

“…A wellknown example was the Ti 3+ self-doped TiO 2 [92], in which the impurity levels introduced by Ti 3+ were located below CB and performed as an electron trap. It is noteworthy that self-doping and defect engineering can deliver numerous coordinately unsaturated sites (CUSs) for the adsorption and activation of molecules [93,94].…”