Although TiO2-based nanostructures with unique chemical and physical properties exhibit great promise in water treatment and energy conversion/storage,there still exist some limitations.In order to further improve the...Although TiO2-based nanostructures with unique chemical and physical properties exhibit great promise in water treatment and energy conversion/storage,there still exist some limitations.In order to further improve the photochemical properties,one-dimension TiO2 nanoarrays on the substrate are primarily combined with graphene by various preparation technologies.The composite coating has exhibited extraordinary photocatalytic abilities in the degradation of organic pollutants into less toxic compounds,antimicrobial activity and adsorption capacity in water treatment.Especially,it is easy to recycle after photocatalytic reaction.Additionally,TiO2 nanoarrays/graphene on the substrate(especially flexible substrate)could provide potential opportunities for flexible-device fabrication with excellent photovoltaic conversion efficiency and electrochemical performance in energy conversion/storage devices.As far as we know,the relevant reviews have rarely been reported.Here,we present a comprehensive review on the preparation of TiO2 nanoarrays or TiO2 nanoarrays/graphene,and their application and mechanism in water treatment and energy conversion/storage.展开更多
文章模拟了CO_(2)与绿氢合成甲醇的过程,提出了CO_(2)储能密度指标,研究了多个参数对甲醇储能性能的影响。研究结果表明:系统能效和甲醇能量产率随着电解水效率、单程CO_(2)转化率、电解水压力和CO_(2)初始压力的升高而升高,随着甲醇合...文章模拟了CO_(2)与绿氢合成甲醇的过程,提出了CO_(2)储能密度指标,研究了多个参数对甲醇储能性能的影响。研究结果表明:系统能效和甲醇能量产率随着电解水效率、单程CO_(2)转化率、电解水压力和CO_(2)初始压力的升高而升高,随着甲醇合成压力的升高而降低;CO_(2)储能密度随以上参数的变化趋势与系统能效和甲醇能量产率相反;电解水效率和单程CO_(2)转化率是敏感关键的参数;在最优组合工况下,基于甲醇高位和低位热值的系统能效分别为68.0%和59.6%,CO_(2)储能密度为6.07 k W·h/kg,能量产率为0.108 kg/(k W·h),表明以CO_(2)为原料的电制甲醇的系统能效不够理想,但储能密度优势显著。展开更多
Lithium-air batteries have attracted significant interest for applications in high energy density mobile power supplies, yet there are considerable challenges to the development of rechargeable Li-air batteries with s...Lithium-air batteries have attracted significant interest for applications in high energy density mobile power supplies, yet there are considerable challenges to the development of rechargeable Li-air batteries with stable cycling performance under ambient conditions. Here we report a three-dimensional (3D) hydrophobic graphene membrane as a moisture-resistive cathode for high performance Li-air batteries. The 3D graphene membrane features a highly interconnected graphene network for efficient charge transport, a highly porous structure for efficient diffusion of oxygen and electrolyte ions, a large specific surface area for high capacity storage of the insulating discharge product, and a network of highly tortuous hydrophobic channels for O2/H20 selectivity. These channels facilitate 02 ingression while retarding moisture diffusion and ensure excellent charge/ discharge cycling stability under ambient conditions. The membrane can thus enable robust Li-air batteries with exceptional performance, including a maximum cathode capacity that exceeds 5,700 mAh/g and excellent recharge cycling behavior (〉2,000 cycles at 140 mAh/g, and 〉100 cycles at 1,400 mAh/g). The graphene membrane air cathode can deliver a lifetime capacity of 100,000-300,000 mAh/g, comparable to that of a typical lithium ion battery cathode. The stable operation of Li-air batteries with significantly improved single charge capacities and lifetime capacities comparable to those of Li-ion batteries may offer an attractive high energy density storage alternative for future mobile power supplies. These batteries may provide much longer battery lives and greatly reduced recharge frequency.展开更多
基金supported by the National Natural Science Foundation for Distinguished Young Scholars (51425204)
文摘Although TiO2-based nanostructures with unique chemical and physical properties exhibit great promise in water treatment and energy conversion/storage,there still exist some limitations.In order to further improve the photochemical properties,one-dimension TiO2 nanoarrays on the substrate are primarily combined with graphene by various preparation technologies.The composite coating has exhibited extraordinary photocatalytic abilities in the degradation of organic pollutants into less toxic compounds,antimicrobial activity and adsorption capacity in water treatment.Especially,it is easy to recycle after photocatalytic reaction.Additionally,TiO2 nanoarrays/graphene on the substrate(especially flexible substrate)could provide potential opportunities for flexible-device fabrication with excellent photovoltaic conversion efficiency and electrochemical performance in energy conversion/storage devices.As far as we know,the relevant reviews have rarely been reported.Here,we present a comprehensive review on the preparation of TiO2 nanoarrays or TiO2 nanoarrays/graphene,and their application and mechanism in water treatment and energy conversion/storage.
文摘文章模拟了CO_(2)与绿氢合成甲醇的过程,提出了CO_(2)储能密度指标,研究了多个参数对甲醇储能性能的影响。研究结果表明:系统能效和甲醇能量产率随着电解水效率、单程CO_(2)转化率、电解水压力和CO_(2)初始压力的升高而升高,随着甲醇合成压力的升高而降低;CO_(2)储能密度随以上参数的变化趋势与系统能效和甲醇能量产率相反;电解水效率和单程CO_(2)转化率是敏感关键的参数;在最优组合工况下,基于甲醇高位和低位热值的系统能效分别为68.0%和59.6%,CO_(2)储能密度为6.07 k W·h/kg,能量产率为0.108 kg/(k W·h),表明以CO_(2)为原料的电制甲醇的系统能效不够理想,但储能密度优势显著。
文摘Lithium-air batteries have attracted significant interest for applications in high energy density mobile power supplies, yet there are considerable challenges to the development of rechargeable Li-air batteries with stable cycling performance under ambient conditions. Here we report a three-dimensional (3D) hydrophobic graphene membrane as a moisture-resistive cathode for high performance Li-air batteries. The 3D graphene membrane features a highly interconnected graphene network for efficient charge transport, a highly porous structure for efficient diffusion of oxygen and electrolyte ions, a large specific surface area for high capacity storage of the insulating discharge product, and a network of highly tortuous hydrophobic channels for O2/H20 selectivity. These channels facilitate 02 ingression while retarding moisture diffusion and ensure excellent charge/ discharge cycling stability under ambient conditions. The membrane can thus enable robust Li-air batteries with exceptional performance, including a maximum cathode capacity that exceeds 5,700 mAh/g and excellent recharge cycling behavior (〉2,000 cycles at 140 mAh/g, and 〉100 cycles at 1,400 mAh/g). The graphene membrane air cathode can deliver a lifetime capacity of 100,000-300,000 mAh/g, comparable to that of a typical lithium ion battery cathode. The stable operation of Li-air batteries with significantly improved single charge capacities and lifetime capacities comparable to those of Li-ion batteries may offer an attractive high energy density storage alternative for future mobile power supplies. These batteries may provide much longer battery lives and greatly reduced recharge frequency.