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.

Sustainable activation of peroxymonosulfate by the Mo(Ⅳ)in MoS_(2) for the remediation of aromatic organic pollutants

Although MoS_(2) has been proved to be a very ideal cocatalyst in advanced oxidation process(AOPs),the activation process of peroxy mono sulfate(PMS)is still inseparable from metal ions which inevitably brings the risk of secondary pollution and it is not conducive to large-scale industrial application.In this study,the commercial MoS_(2),as a durable and efficient catalyst,was used for directly activating PMS to degrade aromatic organic pollutant.The commercial MoS_(2)/PMS catalytic system demonstrated excellent removal efficiency of phenol and the total organic carbon(TOC)residual rate reach to 25%.The degradation rate was significantly reduced if the used MoS_(2) was directly carried out the next cycle experiment without any post-treatment.Interestingly,the commercial MoS_(2) after post-treated with H2 O_(2) can exhibit good stability and recyclability for cyclic degradation of phenol.Furthermore,the mechanism for the activation of PMS had been investigated by density functional theory(DFT)calculation.The renewable Mo4+exposed on the surface of MoS_(2) was deduced as the primary active site,which realized the direct activation of PMS and avoided secondary pollution.Taking into account the reaction cost and efficient activity,the development of commercial MoS_(2) catalytic system is expected to be applied in industrial wastewater.

Z-scheme CdS/WO_(3)on a carbon cloth enabling effective hydrogen evolution

Photocatalytic water splitting for hydrogen(H2)generation is a potential strategy to solve the problem of energy crisis and environmental deterioration.However,powder-like photocatalysts are difficult to recycle,and the agglomeration of particles would affect the photocatalytic activity.Herein,a direct Z-scheme CdS/WO_(3)composite photocatalyst was fabricated based on carbon cloth through a two-step process.With the support of carbon cloth,photocatalysts tend to grow uniformly for further applications.The experimental results showed that the H2 yield of adding one piece of CdS/WO_(3)composite material was 17.28μmol/h,which was 5.5 times as compared to that of pure CdS-loaded carbon cloth material.A cycle experiment was conducted to verify the stability of the asprepared material and the result demonstrated that the H2 generation performance of CdS/WO_(3)decreased slightly after 3 cycles.This work provides new ideas for the development of recyclable photocatalysts and has a positive significance for practical applications.