We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dh...We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dha-COF@Nb_(2)C was fabricated via the in-situ solvothermal growth of Tph-Dha-COF nanostructures on amino-functionalized Nb_(2)C MXene nanoflakes(Nb_(2)C-NH_(2)).The integration of Nb_(2)C significantly extended the visible light absorption of Tph-Dha-COF into the near-infrared region for photocatalytic H_(2)O_(2) production.The Tph-Dha-COF@Nb_(2)C composite demonstrated efficient charge separation,rapid electron transfer,and enhanced oxygen adsorption.Consequently,the Tph-Dha-COF@Nb_(2)C heterojunction exhibited a high H_(2)O_(2) production rate of 1833μmol g^(-1) h^(-1) without sacrificial agents.In-situ Fourier transformed infrared spectroscopy and density functional theory calculations revealed the photocatalytic H_(2)O_(2) production mechanism.The generated H_(2)O_(2) demonstrated enhanced antibacterial activity.This work presents the first application of Nb_(2)C in the photocatalytic synthesis of H_(2)O_(2) and provides a novel strategy for constructing COF-based heterojunctions for photocatalytic H_(2)O_(2) generation and wastewater treatment.展开更多
Separation of ternary C6 cyclic hydrocarbons,i.e.,benzene/cyclohexene/cyclohexane mixtures,is crucial but challenging in the petrochemical industry due to their extremely similar molecular sizes and physical propertie...Separation of ternary C6 cyclic hydrocarbons,i.e.,benzene/cyclohexene/cyclohexane mixtures,is crucial but challenging in the petrochemical industry due to their extremely similar molecular sizes and physical properties.Here,we design and synthesize a new Zn-based metal azolate framework(MAF),MAF-40,with a threedimensional(3D)honeycomb-like framework and 1D sugar-coated-berry type pore channels.By virtue of the strong coordination bonds and abundant trifluoromethyl groups embedded in the pores,MAF-40 exhibits excellent thermal stability(up to 400℃)and acid-base stability(within a pH range of 3–11).Moreover,MAF-40 shows ultrahigh benzene selectivity(38.8)from the ternary benzene/cyclohexene/cyclohexane mixtures,attributed to the strong adsorption affinity from fluorine for benzene and markedly different vip diffusion limited by the small aperture,which are confirmed by computational simulations and infrared spectra.Thus,the results indicated that MAF-40 would be a candidate adsorbent for the separation and purification of benzene from C6 cyclic hydrocarbons,and this work provides a new insight of synthesizing stable MOF materials for separating multicomponent chemical mixtures.展开更多
文摘We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dha-COF@Nb_(2)C was fabricated via the in-situ solvothermal growth of Tph-Dha-COF nanostructures on amino-functionalized Nb_(2)C MXene nanoflakes(Nb_(2)C-NH_(2)).The integration of Nb_(2)C significantly extended the visible light absorption of Tph-Dha-COF into the near-infrared region for photocatalytic H_(2)O_(2) production.The Tph-Dha-COF@Nb_(2)C composite demonstrated efficient charge separation,rapid electron transfer,and enhanced oxygen adsorption.Consequently,the Tph-Dha-COF@Nb_(2)C heterojunction exhibited a high H_(2)O_(2) production rate of 1833μmol g^(-1) h^(-1) without sacrificial agents.In-situ Fourier transformed infrared spectroscopy and density functional theory calculations revealed the photocatalytic H_(2)O_(2) production mechanism.The generated H_(2)O_(2) demonstrated enhanced antibacterial activity.This work presents the first application of Nb_(2)C in the photocatalytic synthesis of H_(2)O_(2) and provides a novel strategy for constructing COF-based heterojunctions for photocatalytic H_(2)O_(2) generation and wastewater treatment.
基金supported by the National Natural Science Foundation of China(Nos.22090061,22488101,22475240,and 22231012)the State Key Laboratory of Catalysis(No.2024SKL-A-010).
文摘Separation of ternary C6 cyclic hydrocarbons,i.e.,benzene/cyclohexene/cyclohexane mixtures,is crucial but challenging in the petrochemical industry due to their extremely similar molecular sizes and physical properties.Here,we design and synthesize a new Zn-based metal azolate framework(MAF),MAF-40,with a threedimensional(3D)honeycomb-like framework and 1D sugar-coated-berry type pore channels.By virtue of the strong coordination bonds and abundant trifluoromethyl groups embedded in the pores,MAF-40 exhibits excellent thermal stability(up to 400℃)and acid-base stability(within a pH range of 3–11).Moreover,MAF-40 shows ultrahigh benzene selectivity(38.8)from the ternary benzene/cyclohexene/cyclohexane mixtures,attributed to the strong adsorption affinity from fluorine for benzene and markedly different vip diffusion limited by the small aperture,which are confirmed by computational simulations and infrared spectra.Thus,the results indicated that MAF-40 would be a candidate adsorbent for the separation and purification of benzene from C6 cyclic hydrocarbons,and this work provides a new insight of synthesizing stable MOF materials for separating multicomponent chemical mixtures.
