The synthesis of high value-added chemical products using CO_(2)and CH_(4)is a promising CO_(2)conversion technology that can reduce greenhouse gas emissions while also alleviating the energy crisis.However,problems s...The synthesis of high value-added chemical products using CO_(2)and CH_(4)is a promising CO_(2)conversion technology that can reduce greenhouse gas emissions while also alleviating the energy crisis.However,problems such as high energy consumption and strict reaction conditions in reforming process hinder the further development of the technology.In this work,carbon-nitrogen based composites were prepared for the first time according to the design principle from morphology to heterojunction,which is innovatively applied in the process of photocatalytic CH4reforming.Firstly,C_(3)N_(4)materials with different dimensions(D) are prepared and applied to a CO_(2)-CH_(4)photocatalytic system.Additionally,the 2D/2D TiO_(2)/g-C_(3)N_(4)heterostructure is constructed with the ultrasonic impregnation method to further improve charge generation,transfer,and separation efficiency.It is worth noting that the yield of CO reaches173.80 μmol g^(-1),and the catalytic performance is improved by 1546% compared to bulk C_(3)N_(4).Moreover,the physical and chemical properties of 2D/2D TiO_(2)/g-C_(3)N_(4)materials are studied using a variety of cha racterization methods.Furthermore,the work fu nction and adsorption energy of different C3N4/TiO_(2)models for CO_(2)adsorption are calculated by density functional theory(DFT).Then,a possible catalytic mechanism for photocatalytic CO_(2)and CH_(4) conversion is proposed based on DFT calculations and experimental results.This work provides a new technical route for the rapid conversion of CO_(2)and CH_(4) at room temperature,as well as a new research concept for achieving carbon neutrality.展开更多
Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water...Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water ecosystem, becomes crucial.展开更多
Chalcogenide glass (ChG) is an attractive material for highly efficient nonlinear photonics,which can cover an ultrabroadband wavelength window from the near-visible to the footprint infrared region. However,it remain...Chalcogenide glass (ChG) is an attractive material for highly efficient nonlinear photonics,which can cover an ultrabroadband wavelength window from the near-visible to the footprint infrared region. However,it remains a challenge to implement highly-efficient and low-threshold optical parametric processes in chip-scale ChG devices due to thermal and light-induced instabilities as well as a high-loss factor in ChG films. Here,we develop a systematic fabrication process for high-performance photonic-chip-integrated ChG devices,by which planarintegrated ChG microresonators with an intrinsic quality (Q) factor above 1 million are demonstrated. In particular,an in situ light-induced annealing method is introduced to overcome the longstanding instability underlying ChG film. In high-Q ChG microresonators,optical parametric oscillations with threshold power as low as 5.4 mW are demonstrated for the first time,to our best knowledge. Our results would contribute to efforts of making efficient and low-threshold optical microcombs not only in the near-infrared as presented but more promisingly in the midinfrared range.展开更多
基金The financial support from the National Natural Science Foundation of China (22178089)the Hunan Provincial Innovation Foundation for Postgraduate (CX20220392)。
文摘The synthesis of high value-added chemical products using CO_(2)and CH_(4)is a promising CO_(2)conversion technology that can reduce greenhouse gas emissions while also alleviating the energy crisis.However,problems such as high energy consumption and strict reaction conditions in reforming process hinder the further development of the technology.In this work,carbon-nitrogen based composites were prepared for the first time according to the design principle from morphology to heterojunction,which is innovatively applied in the process of photocatalytic CH4reforming.Firstly,C_(3)N_(4)materials with different dimensions(D) are prepared and applied to a CO_(2)-CH_(4)photocatalytic system.Additionally,the 2D/2D TiO_(2)/g-C_(3)N_(4)heterostructure is constructed with the ultrasonic impregnation method to further improve charge generation,transfer,and separation efficiency.It is worth noting that the yield of CO reaches173.80 μmol g^(-1),and the catalytic performance is improved by 1546% compared to bulk C_(3)N_(4).Moreover,the physical and chemical properties of 2D/2D TiO_(2)/g-C_(3)N_(4)materials are studied using a variety of cha racterization methods.Furthermore,the work fu nction and adsorption energy of different C3N4/TiO_(2)models for CO_(2)adsorption are calculated by density functional theory(DFT).Then,a possible catalytic mechanism for photocatalytic CO_(2)and CH_(4) conversion is proposed based on DFT calculations and experimental results.This work provides a new technical route for the rapid conversion of CO_(2)and CH_(4) at room temperature,as well as a new research concept for achieving carbon neutrality.
基金supported by the National Natural Science Foundation of China (42090015,42071400,42371339)the International Research Center of Big Data for Sustainable Development Goals (CBAS2022GSP04)+3 种基金the Croucher Foundation (CAS22902/ CAS22HU01)The University of Hong Kong Faculty of Business and Economics and Shenzhen Research Institutes (SZRI2023-CRF04)The University of Hong Kong HKU-100 Scholars Fundthe Seed Fund for Strategic Interdisciplinary Research Scheme Fund。
文摘Water plays a central role in sustaining a thriving human society. Given its immense importance, safeguarding the related water infrastructure such as dams and reservoirs, which ensures the proper functioning of water ecosystem, becomes crucial.
基金National Key Research and Development Program of China (2019YFA0706301)Key Project in Broadband Communication and New Network of the Ministry of Science and Technology (MOST)(2018YFB1801003)+3 种基金National Natural Science Foundation of China (61975242,U2001601)Key Project for Science and Technology of Guangzhou City (201904020048)Science and Technology Planning Project of Guangdong Province (2019A1515010774)Science Foundation of Guangzhou City (202002030103)。
文摘Chalcogenide glass (ChG) is an attractive material for highly efficient nonlinear photonics,which can cover an ultrabroadband wavelength window from the near-visible to the footprint infrared region. However,it remains a challenge to implement highly-efficient and low-threshold optical parametric processes in chip-scale ChG devices due to thermal and light-induced instabilities as well as a high-loss factor in ChG films. Here,we develop a systematic fabrication process for high-performance photonic-chip-integrated ChG devices,by which planarintegrated ChG microresonators with an intrinsic quality (Q) factor above 1 million are demonstrated. In particular,an in situ light-induced annealing method is introduced to overcome the longstanding instability underlying ChG film. In high-Q ChG microresonators,optical parametric oscillations with threshold power as low as 5.4 mW are demonstrated for the first time,to our best knowledge. Our results would contribute to efforts of making efficient and low-threshold optical microcombs not only in the near-infrared as presented but more promisingly in the midinfrared range.
