CdS-based photocatalysts offer an efficient route for simultaneous photocatalytic hydrogen evolution and benzyl alcohol oxidation to value-added chemicals.However,the rapid charge recombination,poor oxidation capabili...CdS-based photocatalysts offer an efficient route for simultaneous photocatalytic hydrogen evolution and benzyl alcohol oxidation to value-added chemicals.However,the rapid charge recombination,poor oxidation capabilities,and strong photocorrosion of CdS,when used alone,can lead to low productivity of H2 and benzaldehyde.Herein,we present a novel S-scheme heterojunction through coupling CdS with Fluorenone-COF as the promising oxidation end.The suitable band level and active center of the fluorenone moiety impart strong oxidative capabilities to the fluorenone-based COFs,enabling them to efficiently catalyze the oxidation of benzyl alcohol with a low reaction energy barrier.Furthermore,the intrinsic electric field of the S-scheme heterojunction significantly improves the separation and mobility of photoinduced charge carriers,while effectively suppressing charge recombination,which in turn reduces the corrosive effect of photogenerated holes on CdS.Consequently,the heterojunction significantly improved the yield of both benzaldehyde and hydrogen.In the presence of Pt as a cocatalyst,the production rates of H2 and benzaldehyde reached 23.38 and 17.36 mmol g^(-1) h^(-1),respectively.This work not only addresses the challenges associated with the utilization of electron holes but also provides an effective green and low-carbon pathway to overcome the challenges of low efficiency and high cost in photocatalytic hydrogen production.展开更多
As an intense picosecond laser pulse irradiates a hydrocarbon target,the protons therein can be accelerated by the radiation pressure as well as the sheath field behind the target.We investigate the effect of the lase...As an intense picosecond laser pulse irradiates a hydrocarbon target,the protons therein can be accelerated by the radiation pressure as well as the sheath field behind the target.We investigate the effect of the laser and hydrocarbon target parameters on proton acceleration with two/threedimensional particle-in-cell simulations.It is found that the resulting two-ion species plasma can generate a multiple peaked charge-separation field that accelerates the protons.In particular,a smaller carbon-to-hydrogen ratio,as well as the thinner and/or lower density of the target,leads to a larger sheath field and thus proton beams with a larger cutoff energy and smoother energy spectrum.These results may be useful in achieving high-flux quasi-monoenergetic proton beams by properly designing the hydrocarbon target.展开更多
The structures and electronic spectra of the derivatives of C60-P-2,4,6-triphenyl borazinc have been studied by using AM 1 method. The calculated results indicate that this kind of compounds has a lower energy differe...The structures and electronic spectra of the derivatives of C60-P-2,4,6-triphenyl borazinc have been studied by using AM 1 method. The calculated results indicate that this kind of compounds has a lower energy difference between HOMO and LUMO. It is found that the electron cloud on unoccupied frontier orbital mainly comes from the contribution of C60, while that on occupied frontier orbital mainly concentrates on the side chain. A long-lived charge-separated state may occur in the objective compounds.展开更多
基金National Natural Science Foundation of China(22378148,52472110,22308113)Natural Science Foundation of Guangdong Province(2024A1515012433)for their support.
文摘CdS-based photocatalysts offer an efficient route for simultaneous photocatalytic hydrogen evolution and benzyl alcohol oxidation to value-added chemicals.However,the rapid charge recombination,poor oxidation capabilities,and strong photocorrosion of CdS,when used alone,can lead to low productivity of H2 and benzaldehyde.Herein,we present a novel S-scheme heterojunction through coupling CdS with Fluorenone-COF as the promising oxidation end.The suitable band level and active center of the fluorenone moiety impart strong oxidative capabilities to the fluorenone-based COFs,enabling them to efficiently catalyze the oxidation of benzyl alcohol with a low reaction energy barrier.Furthermore,the intrinsic electric field of the S-scheme heterojunction significantly improves the separation and mobility of photoinduced charge carriers,while effectively suppressing charge recombination,which in turn reduces the corrosive effect of photogenerated holes on CdS.Consequently,the heterojunction significantly improved the yield of both benzaldehyde and hydrogen.In the presence of Pt as a cocatalyst,the production rates of H2 and benzaldehyde reached 23.38 and 17.36 mmol g^(-1) h^(-1),respectively.This work not only addresses the challenges associated with the utilization of electron holes but also provides an effective green and low-carbon pathway to overcome the challenges of low efficiency and high cost in photocatalytic hydrogen production.
基金the National Key R&D Program of China(No.2016YFA0401100)National Natural Science Foundation of China(Nos.12175154,11875092,and 12005149)+1 种基金the Natural Science Foundation of Top Talent of SZTU(Nos.2019010801001 and 2019020801001)The EPOCH code is used under UK EPSRC contract(EP/G055165/1 and EP/G056803/1).
文摘As an intense picosecond laser pulse irradiates a hydrocarbon target,the protons therein can be accelerated by the radiation pressure as well as the sheath field behind the target.We investigate the effect of the laser and hydrocarbon target parameters on proton acceleration with two/threedimensional particle-in-cell simulations.It is found that the resulting two-ion species plasma can generate a multiple peaked charge-separation field that accelerates the protons.In particular,a smaller carbon-to-hydrogen ratio,as well as the thinner and/or lower density of the target,leads to a larger sheath field and thus proton beams with a larger cutoff energy and smoother energy spectrum.These results may be useful in achieving high-flux quasi-monoenergetic proton beams by properly designing the hydrocarbon target.
文摘The structures and electronic spectra of the derivatives of C60-P-2,4,6-triphenyl borazinc have been studied by using AM 1 method. The calculated results indicate that this kind of compounds has a lower energy difference between HOMO and LUMO. It is found that the electron cloud on unoccupied frontier orbital mainly comes from the contribution of C60, while that on occupied frontier orbital mainly concentrates on the side chain. A long-lived charge-separated state may occur in the objective compounds.
