CONSPECTUS:Electrochemical water purification and pollutant monitoring have garnered significant attention due to their unique technical advantages.The pursuit of safe,efficient,and economically viable catalysts remai...CONSPECTUS:Electrochemical water purification and pollutant monitoring have garnered significant attention due to their unique technical advantages.The pursuit of safe,efficient,and economically viable catalysts remains a critical priority.Titanium dioxide(TiO_(2)),a prototypical transition-metal oxide with substantial industrial importance,is widely recognized as a benchmark catalyst for photochemical reactions.However,its practical application is limited by restricted light absorption and rapid photocarrier recombination.Recently,TiO_(2) has emerged as a promising candidate in electrochemical catalysis,particularly in the fields of energy and environmental science.Its atomic and electronic structures can be precisely engineered through advanced techniques such as nanoscale morphology control,polar-facet engineering,vip-metal doping,and structural-defect modulation.This review examines recent advancements in TiO_(2)-based electrochemical applications,with a focus on water purification and pollutant monitoring.In this Account,we present our efforts to harness facet-and defect-engineered TiO_(2) as electrochemical catalysts for water purification,addressing critical challenges such as low conductivity and poor reactivity.Initially,we demonstrate that facetengineered TiO_(2),specifically designed to expose the high-energy{001}polar facet,facilitates the dissociation of both pollutant and water molecules.This significantly lowers energy barriers and enhances anodic reactions through both direct and indirect pathways,thereby markedly improving water purification efficiency.Furthermore,the dual photochemical and electrochemical functionalities of a single{001}-tailored TiO_(2) electrode enable synergistic UV-light-assisted electrochemical catalysis under low bias conditions,achieving superior energy efficiency and resistance to electrode fouling.Next,we explore the catalytic potential of defect-engineered TiO_(2)(TiO_(2−x)),highlighting the role of titanium(Ti^(3+))and oxygen vacancies(O_(v))in boosting electrochemical water purification.Surface and subsurface defects,characterized by localized atomic disorder and structural distortions,serve as active sites that drive beneficial structural transformations,enriched electronic distribution,enhanced spin−spin correlations,and polaron hopping mechanisms,all of which contribute to improved cathodic reduction.To stabilize these reactive sites under anodic polarization,we propose a practical visible-light-assisted electrochemical catalysis strategy.This approach leverages mild non-band-gap excitation pathways mediated by defect sub-bands,providing enhanced stability and catalytic efficiency.Finally,we identify the challenges associated with the application of self-engineered TiO_(2) in electrochemical water purification and outline directions for future research.Our studies deepen the fundamental understanding of structure−catalysis relationships and exemplify a self-tailoring strategy to advance oxide catalysis without reliance on noble or toxic-metal cocatalysts.By elucidating catalytic mechanisms and adopting innovative synthesis techniques,our insights provide a foundation for designing advanced electrocatalysts.Self-engineered TiO_(2) holds the potential to establish a new paradigm in electrochemical catalysis,opening pathways for transformative solutions in environmental remediation.展开更多
基金supported by the National Natural Science Foundation of China(22076036,52192684 and 52027815)the Anhui Provincial Natural Science Foundation(2308085J23 and 2408055US005).
文摘CONSPECTUS:Electrochemical water purification and pollutant monitoring have garnered significant attention due to their unique technical advantages.The pursuit of safe,efficient,and economically viable catalysts remains a critical priority.Titanium dioxide(TiO_(2)),a prototypical transition-metal oxide with substantial industrial importance,is widely recognized as a benchmark catalyst for photochemical reactions.However,its practical application is limited by restricted light absorption and rapid photocarrier recombination.Recently,TiO_(2) has emerged as a promising candidate in electrochemical catalysis,particularly in the fields of energy and environmental science.Its atomic and electronic structures can be precisely engineered through advanced techniques such as nanoscale morphology control,polar-facet engineering,vip-metal doping,and structural-defect modulation.This review examines recent advancements in TiO_(2)-based electrochemical applications,with a focus on water purification and pollutant monitoring.In this Account,we present our efforts to harness facet-and defect-engineered TiO_(2) as electrochemical catalysts for water purification,addressing critical challenges such as low conductivity and poor reactivity.Initially,we demonstrate that facetengineered TiO_(2),specifically designed to expose the high-energy{001}polar facet,facilitates the dissociation of both pollutant and water molecules.This significantly lowers energy barriers and enhances anodic reactions through both direct and indirect pathways,thereby markedly improving water purification efficiency.Furthermore,the dual photochemical and electrochemical functionalities of a single{001}-tailored TiO_(2) electrode enable synergistic UV-light-assisted electrochemical catalysis under low bias conditions,achieving superior energy efficiency and resistance to electrode fouling.Next,we explore the catalytic potential of defect-engineered TiO_(2)(TiO_(2−x)),highlighting the role of titanium(Ti^(3+))and oxygen vacancies(O_(v))in boosting electrochemical water purification.Surface and subsurface defects,characterized by localized atomic disorder and structural distortions,serve as active sites that drive beneficial structural transformations,enriched electronic distribution,enhanced spin−spin correlations,and polaron hopping mechanisms,all of which contribute to improved cathodic reduction.To stabilize these reactive sites under anodic polarization,we propose a practical visible-light-assisted electrochemical catalysis strategy.This approach leverages mild non-band-gap excitation pathways mediated by defect sub-bands,providing enhanced stability and catalytic efficiency.Finally,we identify the challenges associated with the application of self-engineered TiO_(2) in electrochemical water purification and outline directions for future research.Our studies deepen the fundamental understanding of structure−catalysis relationships and exemplify a self-tailoring strategy to advance oxide catalysis without reliance on noble or toxic-metal cocatalysts.By elucidating catalytic mechanisms and adopting innovative synthesis techniques,our insights provide a foundation for designing advanced electrocatalysts.Self-engineered TiO_(2) holds the potential to establish a new paradigm in electrochemical catalysis,opening pathways for transformative solutions in environmental remediation.
