The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a signifi...The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide.Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift,methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed.展开更多
Closing the carbon loop,through CO_(2)capture and utilization,is a promising route to mitigate climate change.Solar energy is a sustainable energy source which can be exploited to drive catalytic reactions for utilizi...Closing the carbon loop,through CO_(2)capture and utilization,is a promising route to mitigate climate change.Solar energy is a sustainable energy source which can be exploited to drive catalytic reactions for utilizing CO_(2),including converting the CO_(2)into useful products.Solar energy can be harnessed through a range of different pathways to valorize CO_(2).Whilst using solar energy to drive CO_(2)reduction has vast potential to promote catalytic CO_(2)conversions,the progress is limited due to the lack of understanding of property-performance relations as well as feasible material engineering approaches.Herein,we outline the various driving forces involved in photothermal CO_(2)catalysis.The heat from solar energy can be utilized to induce CO_(2)catalytic reduction reactions via the photothermal effect.Further,solar energy can act to modify reaction pathways through light-matter interactions.Light-induced chemical functions have demonstrated the ability to regulate intermediary reaction steps,and thus control the reaction selectivity.Photothermal catalyst structures and specific catalyst design strategies are discussed in this context.This review provides a comprehensive understanding of the heat-light synergy and guidance for rational photothermal catalyst design for CO_(2)utilization.展开更多
Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their po...Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their potential in promoting CO_(2)reduction reaction(CO_(2)RR),however,their low phase stability has limited their application perspective.Herein,we present a reduced graphene oxide(rGO)wrapped CsPbI_3 perovskite nanocrystal(NC)CO_(2)RR catalyst(CsPbI_3/rGO),demonstrating enhanced stability in the aqueous electrolyte.The CsPbI_3/rGO catalyst exhibited>92%Faradaic efficiency toward formate production at a CO_(2)RR current density of~12.7 mA cm^(-2).Comprehensive characterizations revealed the superior performance of the CsPbI_3/rGO catalyst originated from the synergistic effects between the CsPbI_3 NCs and rGO,i.e.,rGO stabilized theα-CsPbI_3 phase and tuned the charge distribution,thus lowered the energy barrier for the protonation process and the formation of~*HCOO intermediate,which resulted in high CO_(2)RR selectivity toward formate.This work shows a promising strategy to rationally design robust metal halide perovskites for achieving efficient CO_(2)RR toward valuable fuels.展开更多
Solar-powered carbon dioxide （CO_2）-to-fuel conversion presents itself as an ideal solution for both CO_2 mit- igation and the rapidly growing world energy demand. In this work, the heating effect of light irradiati...Solar-powered carbon dioxide （CO_2）-to-fuel conversion presents itself as an ideal solution for both CO_2 mit- igation and the rapidly growing world energy demand. In this work, the heating effect of light irradiation onto a bed of supported nickel （Ni） catalyst was utilized to facilitate CO_2 conversion. Ceria （CeO_2）-titania （TiO_2） oxide supports of different compositions were employed and their effects on photothermal CO_2 conver- sion examined, Two factors are shown to be crucial for instigating photothermal CO_2 methanation activity： ① Fine nickel deposits are required for both higher active catalyst area and greater light absorption capacity for the initial heating of the catalyst bed; and ② the presence of defect sites on the support are necessary to promote adsorption of C02 for its subsequent activation, Titania inclusion within the support plays a crucial role in maintaining the oxygen vacancy defect sites on the （titanium-doped） cerium oxide. The combination of elevated light absorption and stabilized reduced states for CO_2 adsorption subsequently invokes effective Dhotothermal CO_2 methanation when the ceria and titania are blended in the ideal ratio（s）.展开更多
The management of chloramine decay and the prevention of nitrification are some of the critical issues faced by water utilities that use chloramine as a disinfectant.In this study,potential association between high pe...The management of chloramine decay and the prevention of nitrification are some of the critical issues faced by water utilities that use chloramine as a disinfectant.In this study,potential association between high performance size exclusion chromatography（HPSEC）data obtained with multiple wavelength Ultraviolet（UV） detection from two drinking water distribution systems in Australia and nitrification occurrence was investigated.An increase in the absorbance signal of HPSEC profiles with UV detection at λ = 230 nm between apparent molecular weights of 200 to 1000 Da was observed at sampling sites that experienced rapid chloramine decay and nitrification while its absorbance signal at λ =254 nm decreased.A chloramine decay index（C.D.I） defined as the ratio of area beneath the HPSEC spectra at two different wavelengths of 230 and 254 nm,was used in assessing chloramine decay occurrences.The C.D.Is of waters at locations that experienced nitrification were consistently higher than locations not experiencing nitrification.A simulated laboratory study showed that the formation of nitrite/nitrate and/or soluble microbial products and/or the release of extracellular polymeric substances（EPS） during nitrification may contribute to the C.D.I.increase.These findings suggest that C.D.I derived from HPSEC with multiple wavelength UV detection could be an informative index to track the occurrence of rapid chloramine decay and nitrification.展开更多
A model is developed to enable estimation of chloramine demand in full scale drinking water supplies based on chemical and microbiological factors that affect chloramine decay rate via nonlinear regression analysis me...A model is developed to enable estimation of chloramine demand in full scale drinking water supplies based on chemical and microbiological factors that affect chloramine decay rate via nonlinear regression analysis method.The model is based on organic character（specific ultraviolet absorbance（SUVA）） of the water samples and a laboratory measure of the microbiological（Fm） decay of chloramine.The applicability of the model for estimation of chloramine residual（and hence chloramine demand） was tested on several waters from different water treatment plants in Australia through statistical test analysis between the experimental and predicted data.Results showed that the model was able to simulate and estimate chloramine demand at various times in real drinking water systems.To elucidate the loss of chloramine over the wide variation of water quality used in this study,the model incorporates both the fast and slow chloramine decay pathways.The significance of estimated fast and slow decay rate constants as the kinetic parameters of the model for three water sources in Australia was discussed.It was found that with the same water source,the kinetic parameters remain the same.This modelling approach has the potential to be used by water treatment operators as a decision support tool in order to manage chloramine disinfection.展开更多
The utilization of Na2S/Na2SO3 mixture as the electrolyte solution to stabilize sulfide anode in a photoelectrochemical cell for hydrogen evolution generally compromises the current-to-hydrogen efficiency（ηcurrent）...The utilization of Na2S/Na2SO3 mixture as the electrolyte solution to stabilize sulfide anode in a photoelectrochemical cell for hydrogen evolution generally compromises the current-to-hydrogen efficiency（ηcurrent） of the system. Here, the employment of a dual-electrolyte system,that is, Na2S/Na2SO3 mixture and p H-neutral Na2SO4 as the respective electrolyte solutions in the anode and cathode chambers of a water splitting cell is demonstrated to suppress the photocorrosion of CuInS2-In2O3-TiO2 nanotube（CISIn2O3-TNT） heterostructure, while simultaneously boosts theηcurrent. Although n-type CIS and In2O3 nanoparticles can be easily formed on TNT array via facile pulse-assisted electrodeposition method, conformal deposition of the nanoparticles homogeneously on the nanotubes wall with preservation of the TNT hollow structure is shown to be essential for achieving efficient charge generation and separation within the heterostructure. In comparison to Na2S/Na2SO3 solution as the sole electrolyte in both the anode and cathode chambers, introduction of dual electrolyte is shown to not only enhance the photostability of the CIS-In2O3-TNT anode, but also lead to near-unity ηcurrentas opposed to the merely 20% ηcurrentof the single-electrolyte system.展开更多
Along with the rapid development of flexible and wearable electronic devices,there have been a strong demand for flexible power sources,which has in turn triggered considerable efforts on the research and development ...Along with the rapid development of flexible and wearable electronic devices,there have been a strong demand for flexible power sources,which has in turn triggered considerable efforts on the research and development of flexible batteries.An ideal flexible battery would have not only just high electrochemical performance but also excellent mechanical deformabilities.Therefore,battery constituent components,chemistry systems,device configurations,and practical applications are all pivotal aspects that should be thoroughly considered.Herein,we systematically and comprehensively review the fundamentals and recent progresses of flexible batteries in terms of these important aspects.Specifically,we first discuss the requirements for constituent components,including the current collector,electrolyte,and separator,in flexible batteries.We then elucidate battery chemistry systems that have been studied for various flexible batteries,including lithium-ion batteries,non-lithium-ion batteries,and high-energy metal batteries.This is followed by discussions on the device configurations for flexible batteries,including onedimensional fiber-shaped,two-dimensional film-shaped,and three-dimensional structural batteries.Finally,we summarize recent efforts in exploring practical applications for flexible batteries.Current challenges and future opportunities for the research and development of flexible batteries are also discussed.展开更多
In this study,we developed a novel confinement-synthesis approach to layered double hydroxide nanodots(LDH-NDs)anchored on carbon nanoparticles,which formed a three-dimensional(3D)interconnected network within a porou...In this study,we developed a novel confinement-synthesis approach to layered double hydroxide nanodots(LDH-NDs)anchored on carbon nanoparticles,which formed a three-dimensional(3D)interconnected network within a porous carbon support derived from pyrolysis of metal-organic frameworks(C-MOF).The resultant LDH-NDs@C-MOF nonprecious metal catalysts were demonstrated to exhibit super-high catalytic performance for oxygen evolution reaction(OER)with excellent operation stability and low overpotential(-230 mV)at an exchange current density of 10 mA·cm^(-2).The observed overpotential for the LDH-NDs@C-MOF is much lower than that of large-sized LDH nanosheets(321 mV),pure carbonized MOF(411 mV),and even commercial RuO_(2)(281 mV).X-ray absorption measurements and density functional theory(DFT)calculations revealed partial charge transfer from Fe^(3+)through an O bridge to Ni^(2+)at the edge of LDH-NDs supported by C-MOF to produce the optimal binding energies for OER intermediates.This,coupled with a large number of exposed active sides and efficient charge and electrolyte/reactant/product transports associated with the porous 3D C-MOF support,significantly boosted the OER performance of the LDH-ND catalyst with respect to its nanosheet counterpart.Apart from the fact that this is the first active side identification for LDH-ND OER catalysts,this work provides a general strategy to enhance activities of nanosheet catalysts by converting them into edge-rich nanodots to be supported by 3D porous carbon architectures.展开更多
Layered materials are particularly attractive for supercapacitors because of their unique physical,electrical and chemical properties.Here,we demonstrate a facile and scalable electrochemical deposition method for waf...Layered materials are particularly attractive for supercapacitors because of their unique physical,electrical and chemical properties.Here,we demonstrate a facile and scalable electrochemical deposition method for wafer-scale synthesis of quasilayered tungstate-doped polypyrrole films(named TALPy)with controllable thickness and size.The as-prepared TALPy film exhibits a high gravimetric density and excellent volumetric capacitance,exceeding many high-performing carbon-and polymerbased film electrodes.Based on combined results of ex-situ X-ray diffraction(XRD),Raman and X-ray photoelectron spectroscopy(XPS),it is determined that TALPy stores charge through an ion intercalation process accompanied by change in oxidation states of polypyrrole backbone,which is referred as intercalation pseudocapacitance.All these results suggest the great promise of electrochemical deposition as a scalable and controllable bottom-up approach for synthesizing quasi-layered conductive organic-inorganic hybrid films for electrochemical energy storage applications with high volumetric performance.展开更多
In this work, we demonstrate the assembly of oxidised carbon nanohybrids(o CNHs) with a commercial cellulose membrane for solid-state supercapacitors. The o CNHs–cellulose membranes were prepared by filtering a water...In this work, we demonstrate the assembly of oxidised carbon nanohybrids(o CNHs) with a commercial cellulose membrane for solid-state supercapacitors. The o CNHs–cellulose membranes were prepared by filtering a water dispersion of o CNHs through the cellulose membrane. The o CNHs were derived from carbon nanotubes via a modified Hummer's method and contained both closed tubes and unzipped tubes, which indicated a hybrid geometrical structure. The solid-state supercapacitor based on the o CNHs–cellulose membranes showed a high areal capacitance of *75 m F/cm^2 at a low scan rate(5 m V/s)and excellent stability for 1,000 cycles.展开更多
A homogeneous layer of Bi_2O_3-Bi_(14)WO_(24) composite(BWO/Bi_2O_3) thin film was fabricated using a combination of electrodeposition and thermal treatment. The evenly distributed Bi14 WO24 component within the Bi_2O...A homogeneous layer of Bi_2O_3-Bi_(14)WO_(24) composite(BWO/Bi_2O_3) thin film was fabricated using a combination of electrodeposition and thermal treatment. The evenly distributed Bi14 WO24 component within the Bi_2O_3 layer was found to be important in stabilising the photoelectrochemical performances of Bi_2O_3 photoanode by promoting the photoelectron transport. The unmodified Bi_2O_3 suffered from severe photocorrosion as proven by X-ray diffraction(XRD) and inductively coupled plasma(ICP) analyses while the composite thin film was active without noticeable activity decay for at least 3 h of illumination. This strategy might be applicable to other photocatalysts with stability issues.展开更多
Addition of reduced graphene oxide(RGO)to P25 TiO_(2)was made and its impacts on photocatalytic oxidation of various organic substances were studied.Although the presence of RGO in TiO_(2)can enhance certain TiO_(2)-b...Addition of reduced graphene oxide(RGO)to P25 TiO_(2)was made and its impacts on photocatalytic oxidation of various organic substances were studied.Although the presence of RGO in TiO_(2)can enhance certain TiO_(2)-based photocatalytic reactions,it is not a universal observation that can be expected in all types of organic substances.The factor of photocatalytic activity enhancement is strongly affected by the various functional groups appeared in the organic substances.In this work,it is realised that the length of alkyl chain in alcohols and carboxylic acids have the minimum influence on the overall activity while the number of hydroxyl groups can promote the further activity enhancement in the presence of RGO.展开更多
文摘The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide.Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift,methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed.
基金supported by the Australian Research Council(ARC)under the Laureate Fellowship Scheme-FL140100081 and ARC Discovery Project DP170102410the support of Scientia Ph D Scholarship from UNSW Sydneythe support of Australia Government Research Training Program(RTP)Scholarship。
文摘Closing the carbon loop,through CO_(2)capture and utilization,is a promising route to mitigate climate change.Solar energy is a sustainable energy source which can be exploited to drive catalytic reactions for utilizing CO_(2),including converting the CO_(2)into useful products.Solar energy can be harnessed through a range of different pathways to valorize CO_(2).Whilst using solar energy to drive CO_(2)reduction has vast potential to promote catalytic CO_(2)conversions,the progress is limited due to the lack of understanding of property-performance relations as well as feasible material engineering approaches.Herein,we outline the various driving forces involved in photothermal CO_(2)catalysis.The heat from solar energy can be utilized to induce CO_(2)catalytic reduction reactions via the photothermal effect.Further,solar energy can act to modify reaction pathways through light-matter interactions.Light-induced chemical functions have demonstrated the ability to regulate intermediary reaction steps,and thus control the reaction selectivity.Photothermal catalyst structures and specific catalyst design strategies are discussed in this context.This review provides a comprehensive understanding of the heat-light synergy and guidance for rational photothermal catalyst design for CO_(2)utilization.
基金financial support by Australian Research Council(ARC)supported by the generous funding from Science and Engineering faculty,QUT。
文摘Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their potential in promoting CO_(2)reduction reaction(CO_(2)RR),however,their low phase stability has limited their application perspective.Herein,we present a reduced graphene oxide(rGO)wrapped CsPbI_3 perovskite nanocrystal(NC)CO_(2)RR catalyst(CsPbI_3/rGO),demonstrating enhanced stability in the aqueous electrolyte.The CsPbI_3/rGO catalyst exhibited>92%Faradaic efficiency toward formate production at a CO_(2)RR current density of~12.7 mA cm^(-2).Comprehensive characterizations revealed the superior performance of the CsPbI_3/rGO catalyst originated from the synergistic effects between the CsPbI_3 NCs and rGO,i.e.,rGO stabilized theα-CsPbI_3 phase and tuned the charge distribution,thus lowered the energy barrier for the protonation process and the formation of~*HCOO intermediate,which resulted in high CO_(2)RR selectivity toward formate.This work shows a promising strategy to rationally design robust metal halide perovskites for achieving efficient CO_(2)RR toward valuable fuels.
基金financially supported by the Australian Research Council under the Laureate Fellowship Scheme (FL140100081)
文摘Solar-powered carbon dioxide （CO_2）-to-fuel conversion presents itself as an ideal solution for both CO_2 mit- igation and the rapidly growing world energy demand. In this work, the heating effect of light irradiation onto a bed of supported nickel （Ni） catalyst was utilized to facilitate CO_2 conversion. Ceria （CeO_2）-titania （TiO_2） oxide supports of different compositions were employed and their effects on photothermal CO_2 conver- sion examined, Two factors are shown to be crucial for instigating photothermal CO_2 methanation activity： ① Fine nickel deposits are required for both higher active catalyst area and greater light absorption capacity for the initial heating of the catalyst bed; and ② the presence of defect sites on the support are necessary to promote adsorption of C02 for its subsequent activation, Titania inclusion within the support plays a crucial role in maintaining the oxygen vacancy defect sites on the （titanium-doped） cerium oxide. The combination of elevated light absorption and stabilized reduced states for CO_2 adsorption subsequently invokes effective Dhotothermal CO_2 methanation when the ceria and titania are blended in the ideal ratio（s）.
基金supported under Australian Research Council's Linkage Projects funding scheme(LP110100459)the provision of in-kind and financial support from the Australian Water Quality Centre(SA Water),Water Corporation(Western Australia),and DCM Process Control
文摘The management of chloramine decay and the prevention of nitrification are some of the critical issues faced by water utilities that use chloramine as a disinfectant.In this study,potential association between high performance size exclusion chromatography（HPSEC）data obtained with multiple wavelength Ultraviolet（UV） detection from two drinking water distribution systems in Australia and nitrification occurrence was investigated.An increase in the absorbance signal of HPSEC profiles with UV detection at λ = 230 nm between apparent molecular weights of 200 to 1000 Da was observed at sampling sites that experienced rapid chloramine decay and nitrification while its absorbance signal at λ =254 nm decreased.A chloramine decay index（C.D.I） defined as the ratio of area beneath the HPSEC spectra at two different wavelengths of 230 and 254 nm,was used in assessing chloramine decay occurrences.The C.D.Is of waters at locations that experienced nitrification were consistently higher than locations not experiencing nitrification.A simulated laboratory study showed that the formation of nitrite/nitrate and/or soluble microbial products and/or the release of extracellular polymeric substances（EPS） during nitrification may contribute to the C.D.I.increase.These findings suggest that C.D.I derived from HPSEC with multiple wavelength UV detection could be an informative index to track the occurrence of rapid chloramine decay and nitrification.
基金supported under Australian Research Council's Linkage Projects funding scheme(LP110100459)the provision of in-kind and financial support from the Australian Water Quality Centre(SA Water),Water Corporation(Western Australia)
文摘A model is developed to enable estimation of chloramine demand in full scale drinking water supplies based on chemical and microbiological factors that affect chloramine decay rate via nonlinear regression analysis method.The model is based on organic character（specific ultraviolet absorbance（SUVA）） of the water samples and a laboratory measure of the microbiological（Fm） decay of chloramine.The applicability of the model for estimation of chloramine residual（and hence chloramine demand） was tested on several waters from different water treatment plants in Australia through statistical test analysis between the experimental and predicted data.Results showed that the model was able to simulate and estimate chloramine demand at various times in real drinking water systems.To elucidate the loss of chloramine over the wide variation of water quality used in this study,the model incorporates both the fast and slow chloramine decay pathways.The significance of estimated fast and slow decay rate constants as the kinetic parameters of the model for three water sources in Australia was discussed.It was found that with the same water source,the kinetic parameters remain the same.This modelling approach has the potential to be used by water treatment operators as a decision support tool in order to manage chloramine disinfection.
基金supported by the Australian Research Council (DP170102895)
文摘The utilization of Na2S/Na2SO3 mixture as the electrolyte solution to stabilize sulfide anode in a photoelectrochemical cell for hydrogen evolution generally compromises the current-to-hydrogen efficiency（ηcurrent） of the system. Here, the employment of a dual-electrolyte system,that is, Na2S/Na2SO3 mixture and p H-neutral Na2SO4 as the respective electrolyte solutions in the anode and cathode chambers of a water splitting cell is demonstrated to suppress the photocorrosion of CuInS2-In2O3-TiO2 nanotube（CISIn2O3-TNT） heterostructure, while simultaneously boosts theηcurrent. Although n-type CIS and In2O3 nanoparticles can be easily formed on TNT array via facile pulse-assisted electrodeposition method, conformal deposition of the nanoparticles homogeneously on the nanotubes wall with preservation of the TNT hollow structure is shown to be essential for achieving efficient charge generation and separation within the heterostructure. In comparison to Na2S/Na2SO3 solution as the sole electrolyte in both the anode and cathode chambers, introduction of dual electrolyte is shown to not only enhance the photostability of the CIS-In2O3-TNT anode, but also lead to near-unity ηcurrentas opposed to the merely 20% ηcurrentof the single-electrolyte system.
基金financial support from The Special Significant Science and Technology Program of Yunnan Province(No.2016HE001-2016HE002).
文摘Along with the rapid development of flexible and wearable electronic devices,there have been a strong demand for flexible power sources,which has in turn triggered considerable efforts on the research and development of flexible batteries.An ideal flexible battery would have not only just high electrochemical performance but also excellent mechanical deformabilities.Therefore,battery constituent components,chemistry systems,device configurations,and practical applications are all pivotal aspects that should be thoroughly considered.Herein,we systematically and comprehensively review the fundamentals and recent progresses of flexible batteries in terms of these important aspects.Specifically,we first discuss the requirements for constituent components,including the current collector,electrolyte,and separator,in flexible batteries.We then elucidate battery chemistry systems that have been studied for various flexible batteries,including lithium-ion batteries,non-lithium-ion batteries,and high-energy metal batteries.This is followed by discussions on the device configurations for flexible batteries,including onedimensional fiber-shaped,two-dimensional film-shaped,and three-dimensional structural batteries.Finally,we summarize recent efforts in exploring practical applications for flexible batteries.Current challenges and future opportunities for the research and development of flexible batteries are also discussed.
基金supported by The ARC(Nos.DP190103881 and FL190100126).
文摘In this study,we developed a novel confinement-synthesis approach to layered double hydroxide nanodots(LDH-NDs)anchored on carbon nanoparticles,which formed a three-dimensional(3D)interconnected network within a porous carbon support derived from pyrolysis of metal-organic frameworks(C-MOF).The resultant LDH-NDs@C-MOF nonprecious metal catalysts were demonstrated to exhibit super-high catalytic performance for oxygen evolution reaction(OER)with excellent operation stability and low overpotential(-230 mV)at an exchange current density of 10 mA·cm^(-2).The observed overpotential for the LDH-NDs@C-MOF is much lower than that of large-sized LDH nanosheets(321 mV),pure carbonized MOF(411 mV),and even commercial RuO_(2)(281 mV).X-ray absorption measurements and density functional theory(DFT)calculations revealed partial charge transfer from Fe^(3+)through an O bridge to Ni^(2+)at the edge of LDH-NDs supported by C-MOF to produce the optimal binding energies for OER intermediates.This,coupled with a large number of exposed active sides and efficient charge and electrolyte/reactant/product transports associated with the porous 3D C-MOF support,significantly boosted the OER performance of the LDH-ND catalyst with respect to its nanosheet counterpart.Apart from the fact that this is the first active side identification for LDH-ND OER catalysts,this work provides a general strategy to enhance activities of nanosheet catalysts by converting them into edge-rich nanodots to be supported by 3D porous carbon architectures.
基金supported by the Australian Research Council Discovery Project(No.DP190101008)Future Fellowship(No.FT190100058)the UNSW Scientia Program.H.B.L.acknowledges the University International Postgraduate Award(UIPA)PhD Scholarship from UNSW Sydney.
文摘Layered materials are particularly attractive for supercapacitors because of their unique physical,electrical and chemical properties.Here,we demonstrate a facile and scalable electrochemical deposition method for wafer-scale synthesis of quasilayered tungstate-doped polypyrrole films(named TALPy)with controllable thickness and size.The as-prepared TALPy film exhibits a high gravimetric density and excellent volumetric capacitance,exceeding many high-performing carbon-and polymerbased film electrodes.Based on combined results of ex-situ X-ray diffraction(XRD),Raman and X-ray photoelectron spectroscopy(XPS),it is determined that TALPy stores charge through an ion intercalation process accompanied by change in oxidation states of polypyrrole backbone,which is referred as intercalation pseudocapacitance.All these results suggest the great promise of electrochemical deposition as a scalable and controllable bottom-up approach for synthesizing quasi-layered conductive organic-inorganic hybrid films for electrochemical energy storage applications with high volumetric performance.
基金supported by Faculty of Engineering,The University of New South Wales and the Australian Research Council Discovery Project(DP160103244)
文摘In this work, we demonstrate the assembly of oxidised carbon nanohybrids(o CNHs) with a commercial cellulose membrane for solid-state supercapacitors. The o CNHs–cellulose membranes were prepared by filtering a water dispersion of o CNHs through the cellulose membrane. The o CNHs were derived from carbon nanotubes via a modified Hummer's method and contained both closed tubes and unzipped tubes, which indicated a hybrid geometrical structure. The solid-state supercapacitor based on the o CNHs–cellulose membranes showed a high areal capacitance of *75 m F/cm^2 at a low scan rate(5 m V/s)and excellent stability for 1,000 cycles.
基金supported by the Australian Research Council under the Laureate Fellowship Scheme(FL140100081)
文摘A homogeneous layer of Bi_2O_3-Bi_(14)WO_(24) composite(BWO/Bi_2O_3) thin film was fabricated using a combination of electrodeposition and thermal treatment. The evenly distributed Bi14 WO24 component within the Bi_2O_3 layer was found to be important in stabilising the photoelectrochemical performances of Bi_2O_3 photoanode by promoting the photoelectron transport. The unmodified Bi_2O_3 suffered from severe photocorrosion as proven by X-ray diffraction(XRD) and inductively coupled plasma(ICP) analyses while the composite thin film was active without noticeable activity decay for at least 3 h of illumination. This strategy might be applicable to other photocatalysts with stability issues.
基金The authors thank the Australian Research Council(ARC)for its financial support through Discovery Project(DP170102895).
文摘Addition of reduced graphene oxide(RGO)to P25 TiO_(2)was made and its impacts on photocatalytic oxidation of various organic substances were studied.Although the presence of RGO in TiO_(2)can enhance certain TiO_(2)-based photocatalytic reactions,it is not a universal observation that can be expected in all types of organic substances.The factor of photocatalytic activity enhancement is strongly affected by the various functional groups appeared in the organic substances.In this work,it is realised that the length of alkyl chain in alcohols and carboxylic acids have the minimum influence on the overall activity while the number of hydroxyl groups can promote the further activity enhancement in the presence of RGO.
