The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a nov...The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a novel magnetically separable Au-loaded CaFe_(2)O_(4)/CoAl LDH heterostructure with strong coulombic interfacial interactions fabricated through a simple two-step process.XRD,XPS and TEM analysis of the synthesized samples were carried out for the structural and morphological characterization.The TEM study confirmed the existence of a firm attachment between the Au nanoparticles with the CaFe_(2)O_(4)/CoAl LDH heterostructures,which provides a unique support due to an exterior confinement effect.Formation of the heterojunction with a different electronic behaviour was also confirmed from an inverted V-shaped M-S plot,suggesting the presence of a large intimate contact interface between CoAl LDH and CaFe_(2)O_(4)to favour the efficient separation and transfer of photoinduced charge pairs.The CoAl LDH-CaFe_(2)O_(4)@Au ternary heterostructure showed a high hydrogen generation rate of 379.1μmol h^(−1),oxygen evolution rate of 205.5μmol h^(−1)and Cr(VI)reduction rate of 99%under visible light irradiation.The CoAl LDH-CaFe_(2)O_(4)@Au heterostructure demonstrated its long-term stability and durability during photocatalytic investigations.The efficient photocatalytic activity of the catalysts was due to the synergistic effect of hot electron transfer by Au nanoparticles and easy mass transport through the interface owing to formation of a p-n junction by increasing the contact area.The mechanism of the photocatalytic activity was also supported by PL,EIS and photocurrent measurements.This work provides a novel strategy to design junction-based nanostructures as a promising photocatalyst for solar energy conversion.展开更多
In recent years, graphitic carbon nitride has become one of the very exciting sustainable materials, due to its unusual properties and promising applications as a heterogeneous catalyst in water splitting and organic ...In recent years, graphitic carbon nitride has become one of the very exciting sustainable materials, due to its unusual properties and promising applications as a heterogeneous catalyst in water splitting and organic contaminant degradation. A variety of modifications have been reported for this nanostructured material with the use of carbonaceous materials to enhance its potential applications. This review summarizes the ongoing developments towards the use of carbonaceous materials like activated carbon (AC), ordered mesoporous carbon (OMC), carbon nanotubes (CNTs), fullerene (C60) and graphene (GE) for the enhancement of the photocatalytic performance of metal free semiconductor photocatalysts because of their special structures and unique electronic properties. Also this review highlights the recent strategies aiming to promote the activity by coupling with polymers (having higher carbon content). Our study reveals that in addition to the charge transfer effects, morphological changes in g-C_(3)N_(4) are also introduced by combination of g-C_(3)N_(4) with carbonaceous materials to tailor its pristine properties and to extend its applications.展开更多
For enhancing solar energy conversion and environmental remediation,noble metal plasmonic photocatalysis originating from the effectual light absorbance and confinement of surface plasmons provides a new promising rou...For enhancing solar energy conversion and environmental remediation,noble metal plasmonic photocatalysis originating from the effectual light absorbance and confinement of surface plasmons provides a new promising route.In the present study,by integrating these two aspects,a series of ternary Ag@Ag_(3)VO_(4)/ZnCr LDH heterostructures have been prepared by an in situ hydrothermal followed by coprecipitation method.In this method,there is self-assembling of Ag_(3)VO_(4) nanoparticles on the brucite surface of the LDH material along with partial reduction of Ag^(+)to Ag.The phase identity,optical response,and morphological structure of the heterostructure photocatalysts were systematically characterized through PXRD,HRTEM,UV-Vis DRS,PL,and XPS methods.The resulting monodisperse Ag nanoparticles deposited on LDH materials offer a heterogeneous interaction at the interface and exhibit high photocatalytic activity towards generation of O_(2) and oxidation of phenol.Evaluation of photocatalytic activity showed that 40 wt% of Ag_(3)VO_(4) modified LDH is the most effective photocatalyst for O_(2) evolution(571μmol)and phenol oxidation(93%).The highly improved photocatalytic performance of the composite was ascribed mainly to the SPR effect of Ag nanoparticles,Schottky barriers formed at the interface of LDH and Ag_(3)VO_(4) nanoparticles,and strong coupling between Ag,Ag_(3)VO_(4) and LDH.The electrochemical studies such as LSV,CV,EIS and Tafel plots further support the high rate of photoactivity towards O_(2) evolution and phenol oxidation.These newly designed plasmonic Ag–LDH nanoheterostructures may offer a promising strategy for maximum light absorption and be authoritative in meeting environmental claims in the future.展开更多
Herein,we disclosed the g-C_(3)N_(4)/LaFeO_(3) nanocomposite photocatalyst,a mediator-free direct Z-scheme photocatalytic system,prepared using a mechanical mixing method with reliable interfacial interactions. The na...Herein,we disclosed the g-C_(3)N_(4)/LaFeO_(3) nanocomposite photocatalyst,a mediator-free direct Z-scheme photocatalytic system,prepared using a mechanical mixing method with reliable interfacial interactions. The nanocomposite formation was determined by X-ray diffraction (XRD),transmission electron microscopy (TEM),and X-ray photoelectron spectroscopy (XPS). The optical properties of the nanohybrids were also characterized using UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. The results clearly indicated that the g-C_(3)N_(4)/LaFeO_(3) nanocomposite was effectively fabricated,with reliable interfacial interactions and a good heterojunction interaction between g-C_(3)N_(4) and LaFeO_(3),which can considerably enhance the photocatalytic activity as compared to pristine g-C_(3)N_(4) and LaFeO_(3). The high HER (1152 μmol h^(−1) g^(−1)) was also confirmed by the PL spectra,Mott–Schottky plot,electrochemical impedance spectroscopy (EIS),and solid–solid interfacial interactions.展开更多
文摘The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a novel magnetically separable Au-loaded CaFe_(2)O_(4)/CoAl LDH heterostructure with strong coulombic interfacial interactions fabricated through a simple two-step process.XRD,XPS and TEM analysis of the synthesized samples were carried out for the structural and morphological characterization.The TEM study confirmed the existence of a firm attachment between the Au nanoparticles with the CaFe_(2)O_(4)/CoAl LDH heterostructures,which provides a unique support due to an exterior confinement effect.Formation of the heterojunction with a different electronic behaviour was also confirmed from an inverted V-shaped M-S plot,suggesting the presence of a large intimate contact interface between CoAl LDH and CaFe_(2)O_(4)to favour the efficient separation and transfer of photoinduced charge pairs.The CoAl LDH-CaFe_(2)O_(4)@Au ternary heterostructure showed a high hydrogen generation rate of 379.1μmol h^(−1),oxygen evolution rate of 205.5μmol h^(−1)and Cr(VI)reduction rate of 99%under visible light irradiation.The CoAl LDH-CaFe_(2)O_(4)@Au heterostructure demonstrated its long-term stability and durability during photocatalytic investigations.The efficient photocatalytic activity of the catalysts was due to the synergistic effect of hot electron transfer by Au nanoparticles and easy mass transport through the interface owing to formation of a p-n junction by increasing the contact area.The mechanism of the photocatalytic activity was also supported by PL,EIS and photocurrent measurements.This work provides a novel strategy to design junction-based nanostructures as a promising photocatalyst for solar energy conversion.
文摘In recent years, graphitic carbon nitride has become one of the very exciting sustainable materials, due to its unusual properties and promising applications as a heterogeneous catalyst in water splitting and organic contaminant degradation. A variety of modifications have been reported for this nanostructured material with the use of carbonaceous materials to enhance its potential applications. This review summarizes the ongoing developments towards the use of carbonaceous materials like activated carbon (AC), ordered mesoporous carbon (OMC), carbon nanotubes (CNTs), fullerene (C60) and graphene (GE) for the enhancement of the photocatalytic performance of metal free semiconductor photocatalysts because of their special structures and unique electronic properties. Also this review highlights the recent strategies aiming to promote the activity by coupling with polymers (having higher carbon content). Our study reveals that in addition to the charge transfer effects, morphological changes in g-C_(3)N_(4) are also introduced by combination of g-C_(3)N_(4) with carbonaceous materials to tailor its pristine properties and to extend its applications.
文摘For enhancing solar energy conversion and environmental remediation,noble metal plasmonic photocatalysis originating from the effectual light absorbance and confinement of surface plasmons provides a new promising route.In the present study,by integrating these two aspects,a series of ternary Ag@Ag_(3)VO_(4)/ZnCr LDH heterostructures have been prepared by an in situ hydrothermal followed by coprecipitation method.In this method,there is self-assembling of Ag_(3)VO_(4) nanoparticles on the brucite surface of the LDH material along with partial reduction of Ag^(+)to Ag.The phase identity,optical response,and morphological structure of the heterostructure photocatalysts were systematically characterized through PXRD,HRTEM,UV-Vis DRS,PL,and XPS methods.The resulting monodisperse Ag nanoparticles deposited on LDH materials offer a heterogeneous interaction at the interface and exhibit high photocatalytic activity towards generation of O_(2) and oxidation of phenol.Evaluation of photocatalytic activity showed that 40 wt% of Ag_(3)VO_(4) modified LDH is the most effective photocatalyst for O_(2) evolution(571μmol)and phenol oxidation(93%).The highly improved photocatalytic performance of the composite was ascribed mainly to the SPR effect of Ag nanoparticles,Schottky barriers formed at the interface of LDH and Ag_(3)VO_(4) nanoparticles,and strong coupling between Ag,Ag_(3)VO_(4) and LDH.The electrochemical studies such as LSV,CV,EIS and Tafel plots further support the high rate of photoactivity towards O_(2) evolution and phenol oxidation.These newly designed plasmonic Ag–LDH nanoheterostructures may offer a promising strategy for maximum light absorption and be authoritative in meeting environmental claims in the future.
文摘Herein,we disclosed the g-C_(3)N_(4)/LaFeO_(3) nanocomposite photocatalyst,a mediator-free direct Z-scheme photocatalytic system,prepared using a mechanical mixing method with reliable interfacial interactions. The nanocomposite formation was determined by X-ray diffraction (XRD),transmission electron microscopy (TEM),and X-ray photoelectron spectroscopy (XPS). The optical properties of the nanohybrids were also characterized using UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. The results clearly indicated that the g-C_(3)N_(4)/LaFeO_(3) nanocomposite was effectively fabricated,with reliable interfacial interactions and a good heterojunction interaction between g-C_(3)N_(4) and LaFeO_(3),which can considerably enhance the photocatalytic activity as compared to pristine g-C_(3)N_(4) and LaFeO_(3). The high HER (1152 μmol h^(−1) g^(−1)) was also confirmed by the PL spectra,Mott–Schottky plot,electrochemical impedance spectroscopy (EIS),and solid–solid interfacial interactions.
