Photocatalysis based on semiconductors has recently been receiving considerable research interest because of its extensive applications in environmental remediation and renewable energy generation.Various semiconducto...Photocatalysis based on semiconductors has recently been receiving considerable research interest because of its extensive applications in environmental remediation and renewable energy generation.Various semiconductor-based materials that are vital to solar energy utilization have been extensively investigated,among which titanium oxide(TiO_(2))has attracted considerable attention because of its exceptional physicochemical characteristics.However,the sluggish responsiveness to visible light in the solar spectrum and the inefficient separation of photoinduced electron-hole pairs hamper the practical application of TiO_(2) materials.To overcome the aforementioned serious drawbacks of TiO_(2),numerous strategies,such as doping with foreign atoms,particularly nitrogen(N),have been improved in the past few decades.This review aims to provide a comprehensive update and description of the recent developments of N-doped TiO_(2) materials for visible lightresponsive photocatalysis,such as(1)the preparation of N-doped/co-doped TiO_(2) photocatalysts and(2)mechanistic studies on the reasons for visible light response.Furthermore,the most recent and significant advances in the field of solar energy applications of modified N-doped TiO_(2) are summarized.The analysis indicated the critical need for further development of these types of materials for the solar-to-energy conversion,particularly for water splitting purposes.展开更多
In this study,different carbon quantum dots(CQDs)/NaBiO3 hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively.These hy...In this study,different carbon quantum dots(CQDs)/NaBiO3 hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively.These hybrid materials exhibit an enhanced photocatalytic reduction of hexavalent chromium(Cr(Ⅵ))in the aqueous medium.Zero-dimensional nanoparticles of CQDs were embedded within the two-dimensional NaBiO3 nanosheets by the hydrothermal process.Compared with that of the pure NaBiO3 nanosheets,the photocatalytic performance of the hybrid catalysts was significantly high and 6 wt.%CQDs/NaBiO3 catalyst exhibited better photocatalytic performance.We performed the first-principles density functional theory calculations to study the interfacial properties of pure NaBiO3 nanosheets and hybrid photocatalysts,and confirmed the CQDs played an important role in the CQDs/NaBiO3 composites.The experimental results indicated that the enhanced reduction of Cr(Ⅵ)was probably due to the high loading of CQDs(electron acceptor)on NaBiO3,which made NaBiO3 nanomaterials to respond in visible light and significantly improved their electron-hole separation efficiency.展开更多
As a prospective visible-light-responsive photochemical material,graphitic carbon nitride(g-C_(3)N_(4))has become a burgeoning research hot topics and aroused a wide interest as a metal-free semiconductor in the area ...As a prospective visible-light-responsive photochemical material,graphitic carbon nitride(g-C_(3)N_(4))has become a burgeoning research hot topics and aroused a wide interest as a metal-free semiconductor in the area of energy utilization and conversion,environmental protection due to its unique properties,such as facile synthesis,high physicochemical stability,excellent electronic band structure,and sustainability.However,the shortcomings of high recombination rate of charge carriers,relatively low electrical conductivity and visible light absorption impede its practical application.Various strategies,such as surface photosensitization,heteroatom deposition,semiconductor hybridization,etc.,have been applied to overcome the barriers.Among all the strategies,functional nanocarbon materials with various dimensions(0D~3D)attract much attention as modifiers of g-C_(3)N_(4)due to their unique electronic properties,optical properties,and easy functionalization.More importantly,the properties of these functional nanocarbon materials can be tuned by various dimensions and thus there will be a way to overcome the defects of g-C_(3)N_(4)by choosing different dimensional carbon materials.Distinguishing from some present reviews,this review starts with the fundamental physicochemical characteristics of g-C_(3)N_(4)materials,followed by analyzing the advantages of functional nanocarbon materials modifying gC_(3)N_(4).Then,we present a systematic introduction to various dimensional carbon materials.The design philosophy of carbon/g-C_(3)N_(4)composites and the advanced studies are exemplified in detail.Finally,a nichetargeting summary and outlook on the major challenges,opportunities for future research in high-powered carbon/g-C_(3)N_(4)composites was proposed.展开更多
The widely used photocatalytic self-cleaning coating materials are often made of polymers and polymer based composites,where the photocatalyst immobilization occurs with macromolecules.However,these organic polymers a...The widely used photocatalytic self-cleaning coating materials are often made of polymers and polymer based composites,where the photocatalyst immobilization occurs with macromolecules.However,these organic polymers are often unstable under exposure to UV irradiation and easily degraded by reactive radicals produced in the photocatalytic reaction.In order to solve this problem,in this paper,we present the facile preparation of a multifunctional coating with dual superhydrophobic and photocatalytic properties,where the fixation and the hydrophobization of the plasmonic Ag-TiO2 photocatalyst particles with visible light activity was performed with non-water soluble sulfur,which is a cheap and easily available material.The resulted novel nanocomposite with rough and nano-tructured surface roughness(1.25–2.45 nm determined by small-angle X-ray scattering)has sufficient low surface energy(3.3 mJ/m2)for superhydrophobic(θ=151.1°v)properties.Moreover,in contrast of the organic and expensive fluoropolymer based composites,this non-wetting nature was durable,because the measured was higher than 150°during the long-term LED(λmax=405 nm)light irradiation.展开更多
Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level....Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level. The binary sol was then intercalated into interspaces of polyaniline （PANI） by means of in-situ polymerization of aniline. Conglomeration of the TiO2-V2O5 dusters during the calcination process was avoided because of the wrap of polyaniline. The surface mor- phology, the crystal phases, the structure, and the absorption spectra of （PANI）,/TiO2-V2O5 and the composite catalyst were studied using SEM, XRD, FT-IR, and UV-Vis. The photoactivity of the prepared catalyst under UV and visible light irradiation were evaluated by decolorization of methylene blue （MB） solution. The results showed that the composite catalyst displayed a homogeneous anatase phase, and the vanadium pentoxide species was highly dispersed in the TiO2 phase. The composite catalyst responded to visible light because of the narrowed band gap. In this study, the catalyst with the sol volume ratio of TiO2： V2O5 = 10：1 presented the best photocatalytic activity.展开更多
Metalenses with achromatic performance offer a new opportunity for high-quality imaging with an ultracompact configuration;however,they suffer from complex fabrication processes and low focusing efficiency.In this stu...Metalenses with achromatic performance offer a new opportunity for high-quality imaging with an ultracompact configuration;however,they suffer from complex fabrication processes and low focusing efficiency.In this study,we propose an efficient design method for achromatic microlenses on a wavelength scale using materials with low dispersion,an adequately designed convex surface,and a thickness profile distribution.By taking into account the absolute chromatic aberration,relative focal length shift(FLS),and numerical aperture(NA),microlens with a certain focal length can be realized through our realized map of geometric features.Accordingly,the designed achromatic microlenses with low-dispersion fused silica were fabricated using a focused ion beam,and precise surface profiles were obtained.The fabricated microlenses exhibited a high average focusing efficiency of 65%at visible wavelengths of 410-680 nm and excellent achromatic capability via white light imaging.Moreover,the design exhibited the advantages of being polarization-insensitive and near-diffraction-limited.These results demonstrate the effectiveness of our proposed achromatic microlens design approach,which expands the prospects of miniaturized optics such as virtual and augmented reality,ultracompact microscopes,and biological endoscopy.展开更多
Photocatalysis is one of the most promising methods owing to its great potential to relieve environmental issue. To construct efficient photocatalyst with low energy consumption, mild catalytic conditions, and stable ...Photocatalysis is one of the most promising methods owing to its great potential to relieve environmental issue. To construct efficient photocatalyst with low energy consumption, mild catalytic conditions, and stable chemical properties are highly desired. In this work, a novel, highly active and environmental friendly mesoporous photocatalyst Bi4O5Br2/SBA-15 was synthesized by hydrothermal method, and its characteristics and visible-light catalytic activity were investigated. The synthesized photocatalyst consisted of Langmuir type IV hysteresis loops, which was confirmed to be a composite material with mesoporous structure. It exhibited a high visible-light absorption intensity and a low recombination rate of photo-generated electrons and holes. When the mass ratio of Bi/SiO2 was 30/100 during the synthesis, the obtained photocatalyst (Bi30/SBA-15) reflected the fastest Rhodamine B (RhB) removal rate and achieved 100% decolorization of RhB by both adsorption and degradation process. This high decolorization efficiency can also be maintained and realized by recycling the used composite in practice. The enhanced visible-light photocatalytic activity of novel Bi4O5Br2/SBA-15 photocatalyst can be ascribed to the existing active sites both inside and outside SBA-15 which enhanced the separation of photo-generated electrons and holes.展开更多
Thanks to their record high refractive index and giant optical anisotropy,van der Waals(vdW)materials have accelerated the development of nanophotonics.However,traditional high refractive index materials,such as titan...Thanks to their record high refractive index and giant optical anisotropy,van der Waals(vdW)materials have accelerated the development of nanophotonics.However,traditional high refractive index materials,such as titanium dioxide(TiO_(2)),still dominate in the most important visible range.This is due to the current lack of transparent vdW materials across the entire visible spectrum.In this context,we propose that germanium disulfide(GeS_(2))could offer a significant breakthrough.With its high refractive index,negligible losses,and biaxial optical anisotropy across the whole visible range,GeS_(2)has the potential to complement TiO2 and close the application gap of vdW materials in the visible spectrum.The addition of GeS_(2)could have a profound impact on the design of van der Waals nanophotonic circuits for any operation wavelength from ultraviolet to infrared,emphasizing the significance of the potential impact of GeS_(2)on the field of nanophotonics.展开更多
Particulate photocatalytic overall water splitting(OWS)represents a promising way to generate green hydrogen for solar energy storage,attracting considerable attention due to its low operational cost,simplicity,and po...Particulate photocatalytic overall water splitting(OWS)represents a promising way to generate green hydrogen for solar energy storage,attracting considerable attention due to its low operational cost,simplicity,and potential for scalable application.To construct efficient systems capable of achieving reasonable energy efficiency amenable to the economic feasibility,it is a prerequisite that the band gap of photocatalysts used should be narrow to guarantee the efficient absorption of incident light.However,the sluggish charge separation remains the main challenge due to the reduced driving force caused by the decreased band gap.This minireview summarizes the latest advances(over the past 5 years)of inorganic photocatalysts with visible-light response beyond 500 nm to construct powder-suspended OWS systems.Additionally,various strategies to improve charge separation and suppress the backward reaction are elaborated,including defect and morphological control,cocatalyst design and surface engineering strategies.Furthermore,challenges and prospects in the developing efficientOWSsystems are discussed to inspire future research toward the rational design of photocatalytic OWS systems.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21633009,21925206,21901240)the National Key Research and Development Program of China(No.2020YFA0406102)。
文摘Photocatalysis based on semiconductors has recently been receiving considerable research interest because of its extensive applications in environmental remediation and renewable energy generation.Various semiconductor-based materials that are vital to solar energy utilization have been extensively investigated,among which titanium oxide(TiO_(2))has attracted considerable attention because of its exceptional physicochemical characteristics.However,the sluggish responsiveness to visible light in the solar spectrum and the inefficient separation of photoinduced electron-hole pairs hamper the practical application of TiO_(2) materials.To overcome the aforementioned serious drawbacks of TiO_(2),numerous strategies,such as doping with foreign atoms,particularly nitrogen(N),have been improved in the past few decades.This review aims to provide a comprehensive update and description of the recent developments of N-doped TiO_(2) materials for visible lightresponsive photocatalysis,such as(1)the preparation of N-doped/co-doped TiO_(2) photocatalysts and(2)mechanistic studies on the reasons for visible light response.Furthermore,the most recent and significant advances in the field of solar energy applications of modified N-doped TiO_(2) are summarized.The analysis indicated the critical need for further development of these types of materials for the solar-to-energy conversion,particularly for water splitting purposes.
基金the funding provided by Key-Area Research and Development Program of Guangdong ProvinceResearch Project of Guangzhou Municipal Science and Technology Bureau+1 种基金the National Natural Science Foundation of ChinaNational Key R&D Program of China(No.2019YFC0408605)。
文摘In this study,different carbon quantum dots(CQDs)/NaBiO3 hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively.These hybrid materials exhibit an enhanced photocatalytic reduction of hexavalent chromium(Cr(Ⅵ))in the aqueous medium.Zero-dimensional nanoparticles of CQDs were embedded within the two-dimensional NaBiO3 nanosheets by the hydrothermal process.Compared with that of the pure NaBiO3 nanosheets,the photocatalytic performance of the hybrid catalysts was significantly high and 6 wt.%CQDs/NaBiO3 catalyst exhibited better photocatalytic performance.We performed the first-principles density functional theory calculations to study the interfacial properties of pure NaBiO3 nanosheets and hybrid photocatalysts,and confirmed the CQDs played an important role in the CQDs/NaBiO3 composites.The experimental results indicated that the enhanced reduction of Cr(Ⅵ)was probably due to the high loading of CQDs(electron acceptor)on NaBiO3,which made NaBiO3 nanomaterials to respond in visible light and significantly improved their electron-hole separation efficiency.
基金supported by the Startup Foundation of China(3160011181808)。
文摘As a prospective visible-light-responsive photochemical material,graphitic carbon nitride(g-C_(3)N_(4))has become a burgeoning research hot topics and aroused a wide interest as a metal-free semiconductor in the area of energy utilization and conversion,environmental protection due to its unique properties,such as facile synthesis,high physicochemical stability,excellent electronic band structure,and sustainability.However,the shortcomings of high recombination rate of charge carriers,relatively low electrical conductivity and visible light absorption impede its practical application.Various strategies,such as surface photosensitization,heteroatom deposition,semiconductor hybridization,etc.,have been applied to overcome the barriers.Among all the strategies,functional nanocarbon materials with various dimensions(0D~3D)attract much attention as modifiers of g-C_(3)N_(4)due to their unique electronic properties,optical properties,and easy functionalization.More importantly,the properties of these functional nanocarbon materials can be tuned by various dimensions and thus there will be a way to overcome the defects of g-C_(3)N_(4)by choosing different dimensional carbon materials.Distinguishing from some present reviews,this review starts with the fundamental physicochemical characteristics of g-C_(3)N_(4)materials,followed by analyzing the advantages of functional nanocarbon materials modifying gC_(3)N_(4).Then,we present a systematic introduction to various dimensional carbon materials.The design philosophy of carbon/g-C_(3)N_(4)composites and the advanced studies are exemplified in detail.Finally,a nichetargeting summary and outlook on the major challenges,opportunities for future research in high-powered carbon/g-C_(3)N_(4)composites was proposed.
基金financially supported by the Hungarian Scientific Research Fund(OTKA)K 116323,PD 116224the project of GINOP-2.3.2-15-2016-00013+1 种基金the UNKP-18-4 New National Excellence Program of the Ministry of Human Capacitiesby the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and the Ministry of Human Capacities,Hungary(No.20391-3/2018/FEKUSTRAT).
文摘The widely used photocatalytic self-cleaning coating materials are often made of polymers and polymer based composites,where the photocatalyst immobilization occurs with macromolecules.However,these organic polymers are often unstable under exposure to UV irradiation and easily degraded by reactive radicals produced in the photocatalytic reaction.In order to solve this problem,in this paper,we present the facile preparation of a multifunctional coating with dual superhydrophobic and photocatalytic properties,where the fixation and the hydrophobization of the plasmonic Ag-TiO2 photocatalyst particles with visible light activity was performed with non-water soluble sulfur,which is a cheap and easily available material.The resulted novel nanocomposite with rough and nano-tructured surface roughness(1.25–2.45 nm determined by small-angle X-ray scattering)has sufficient low surface energy(3.3 mJ/m2)for superhydrophobic(θ=151.1°v)properties.Moreover,in contrast of the organic and expensive fluoropolymer based composites,this non-wetting nature was durable,because the measured was higher than 150°during the long-term LED(λmax=405 nm)light irradiation.
文摘Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level. The binary sol was then intercalated into interspaces of polyaniline （PANI） by means of in-situ polymerization of aniline. Conglomeration of the TiO2-V2O5 dusters during the calcination process was avoided because of the wrap of polyaniline. The surface mor- phology, the crystal phases, the structure, and the absorption spectra of （PANI）,/TiO2-V2O5 and the composite catalyst were studied using SEM, XRD, FT-IR, and UV-Vis. The photoactivity of the prepared catalyst under UV and visible light irradiation were evaluated by decolorization of methylene blue （MB） solution. The results showed that the composite catalyst displayed a homogeneous anatase phase, and the vanadium pentoxide species was highly dispersed in the TiO2 phase. The composite catalyst responded to visible light because of the narrowed band gap. In this study, the catalyst with the sol volume ratio of TiO2： V2O5 = 10：1 presented the best photocatalytic activity.
基金supported by grants from the National Key Research and Development Program of China(2022YFB3806000)the National Natural Science Foundation of China(52325208 and 11974203)the Beijing Municipal Science and Technology Project(Z191100004819002).
文摘Metalenses with achromatic performance offer a new opportunity for high-quality imaging with an ultracompact configuration;however,they suffer from complex fabrication processes and low focusing efficiency.In this study,we propose an efficient design method for achromatic microlenses on a wavelength scale using materials with low dispersion,an adequately designed convex surface,and a thickness profile distribution.By taking into account the absolute chromatic aberration,relative focal length shift(FLS),and numerical aperture(NA),microlens with a certain focal length can be realized through our realized map of geometric features.Accordingly,the designed achromatic microlenses with low-dispersion fused silica were fabricated using a focused ion beam,and precise surface profiles were obtained.The fabricated microlenses exhibited a high average focusing efficiency of 65%at visible wavelengths of 410-680 nm and excellent achromatic capability via white light imaging.Moreover,the design exhibited the advantages of being polarization-insensitive and near-diffraction-limited.These results demonstrate the effectiveness of our proposed achromatic microlens design approach,which expands the prospects of miniaturized optics such as virtual and augmented reality,ultracompact microscopes,and biological endoscopy.
文摘Photocatalysis is one of the most promising methods owing to its great potential to relieve environmental issue. To construct efficient photocatalyst with low energy consumption, mild catalytic conditions, and stable chemical properties are highly desired. In this work, a novel, highly active and environmental friendly mesoporous photocatalyst Bi4O5Br2/SBA-15 was synthesized by hydrothermal method, and its characteristics and visible-light catalytic activity were investigated. The synthesized photocatalyst consisted of Langmuir type IV hysteresis loops, which was confirmed to be a composite material with mesoporous structure. It exhibited a high visible-light absorption intensity and a low recombination rate of photo-generated electrons and holes. When the mass ratio of Bi/SiO2 was 30/100 during the synthesis, the obtained photocatalyst (Bi30/SBA-15) reflected the fastest Rhodamine B (RhB) removal rate and achieved 100% decolorization of RhB by both adsorption and degradation process. This high decolorization efficiency can also be maintained and realized by recycling the used composite in practice. The enhanced visible-light photocatalytic activity of novel Bi4O5Br2/SBA-15 photocatalyst can be ascribed to the existing active sites both inside and outside SBA-15 which enhanced the separation of photo-generated electrons and holes.
基金K.S.N.acknowledges support from the Ministry of Education,Singapore(Research Centre of Excellence award to the Institute for Functional Intelligent Materials,I-FIM,project No.EDUNC-33-18-279-V12)the National Research Foundation,Singapore under its AI Singapore Programme(AISG Award No:AISG3-RP-2022-028)the Royal Society(UK,grant number RSRP\R\190000).
文摘Thanks to their record high refractive index and giant optical anisotropy,van der Waals(vdW)materials have accelerated the development of nanophotonics.However,traditional high refractive index materials,such as titanium dioxide(TiO_(2)),still dominate in the most important visible range.This is due to the current lack of transparent vdW materials across the entire visible spectrum.In this context,we propose that germanium disulfide(GeS_(2))could offer a significant breakthrough.With its high refractive index,negligible losses,and biaxial optical anisotropy across the whole visible range,GeS_(2)has the potential to complement TiO2 and close the application gap of vdW materials in the visible spectrum.The addition of GeS_(2)could have a profound impact on the design of van der Waals nanophotonic circuits for any operation wavelength from ultraviolet to infrared,emphasizing the significance of the potential impact of GeS_(2)on the field of nanophotonics.
基金supported by the National Natural Science Foundation of China(grant nos.22279138,22472072,and 22332005)supported by the Special Fund of Basic Scientific Research expenses of undergraduate universities in Liaoning Province and the Scientific Research Project of the Liaoning Normal University(grant nos.24GDL005,LJ212410165056,and 24TD003).
文摘Particulate photocatalytic overall water splitting(OWS)represents a promising way to generate green hydrogen for solar energy storage,attracting considerable attention due to its low operational cost,simplicity,and potential for scalable application.To construct efficient systems capable of achieving reasonable energy efficiency amenable to the economic feasibility,it is a prerequisite that the band gap of photocatalysts used should be narrow to guarantee the efficient absorption of incident light.However,the sluggish charge separation remains the main challenge due to the reduced driving force caused by the decreased band gap.This minireview summarizes the latest advances(over the past 5 years)of inorganic photocatalysts with visible-light response beyond 500 nm to construct powder-suspended OWS systems.Additionally,various strategies to improve charge separation and suppress the backward reaction are elaborated,including defect and morphological control,cocatalyst design and surface engineering strategies.Furthermore,challenges and prospects in the developing efficientOWSsystems are discussed to inspire future research toward the rational design of photocatalytic OWS systems.
