Simultaneous hydrogen production with the selective oxidation of benzyl alcohol to benzaldehyde by a noble‐metal‐free photocatalyst VC/CdS nanowires

In this work we used CdS NWs(nanowires)with vanadium carbide(VC)attached via facile electrostatic self‐assembly and calcination method.The results showed that compared to pristine CdS NWs,the photocatalytic activity of CdS NWs loaded with the particular amount of VC was dramatically enhanced.Among them,the VC/CS‐15 indicated the highest enhancement for simultaneous production of H2 with selective oxidation of benzyl alcohol(BO)into benzaldehyde(BD).The highest hydrogen evolution rate of 20.5 mmol g^(-1)h^(-1)was obtained with more than 99%selectivity for BD production under visible light(λ˃420 nm)irradiation for 2 h,which was almost 661 times higher than the pristine CdS NWs.This enhancement of photocatalytic activity is due to the VC,which provides a favorable attraction for BO by lowering the zeta potential,along with the active site for hydrogen production,and retard the recombination of electron‐hole pairs by increasing the conductivity of the photocatalyst.Moreover,the apparent quantum efficiency(AQE)of VC/CS‐15 for BD and H_(2)production at monochromatic 420 nm is about 7.5%.At the end of the hydrogen evolution test,the selective oxidation with more than 99%selectivity was obtained.It hopes this work will prove its future significance and move scientific community toward a more economical way for achieving the commercialization of H_(2) by photocatalysis.

Efficient photocatalytic NADH regeneration with Rh-loaded Z-scheme mediator-free system

Nicotinamide adenine dinucleotide(NADH)regeneration is necessary for the sustainable application of enzymatic industry.The Rh-based complex[Cp^(*)Rh(bpy)(H)]+has been widely used as an important mediator in NADH regeneration systems,but it is limited by complexity and high cost.Here,a Z-scheme was constructed by loading Rh onto carbon nitride nanosheets/carbon nitride quantum dots(CN-CNQD).The resultant catalyst achieved a high yield of NADH in a mediator-free(M-free)system of 0.283 mmol L^(−1) g^(−1) min^(−1),which is 5.29 times that of pure CN.ADH enzyme introduction experiments confirmed that the enzyme active product 1,4-NADH could reach 34.21%selectivity in the M-free system.Mechanism research revealed that the heterojunction between CNs and CNQDs improved the NADH regeneration activity in the traditional M-involved system,while Rh loading was proved to optimize the yield and selectivity of 1,4-NADH in M-free system.The immobilized Rh shows more competitiveness than[Cp^(*)Rh(bpy)(H)]^(+).This study contributes to the construction of an M-free system for further application in greener,lower-cost enzymatic processes.

Fluorinated inverse opal carbon nitride combined with vanadium pentoxide as a Z-scheme photocatalyst with enhanced photocatalytic activity

In this work,Z-scheme V_(2)O_(5) loaded fluorinated inverse opal carbon nitride(IO F-CN/V_(2)O_(5)) was synthesized as a product of ternary collaborative modification with heterostructure construction,element doping and inverse opal structure.The catalyst presented the highest photocatalytic activity and rate constant for degradation of typical organic pollutants Rhodamine B(RhB)and was also used for the efficient removal of antibiotics,represented by norfloxacin(NOR),sulfadiazine(SD)and levofloxacin(LVX).Characterizations confirmed its increased specific surface area,narrowed bandgap,and enhanced visible light utilization capacity.Further mechanism study including band structure study and electron paramagnetic resonance(EPR)proved the successful construction of Z-scheme heterojunction,which improved photogenerated charge carrier migration and provide sufficient free radicals for the degradation process.The combination of different modifications contributed to the synergetic improvement of removal efficiency towards different organic pollutants.