为了实现竹屑热解三态产物品质最优化，该文研究了竹屑250～950℃热解多联产的产物分布规律和演变特性，通过分析焦孔隙结构与分形维数演变规律对竹屑热解过程进行了探讨。结果表明，竹屑在较低温度下热解释放出大量的 CO 和 CO2，同时...为了实现竹屑热解三态产物品质最优化，该文研究了竹屑250～950℃热解多联产的产物分布规律和演变特性，通过分析焦孔隙结构与分形维数演变规律对竹屑热解过程进行了探讨。结果表明，竹屑在较低温度下热解释放出大量的 CO 和 CO2，同时生成乙酸、糠醛和酮类物质；450～650℃之间，木质素大量分解使得 H2和 CH4含量上升，液体产物中苯酚类物质含量迅速增加，并开始出现萘、茚等物质；750℃后挥发分二次反应加剧，CO相对含量升高。650℃前，生物炭比表面积与总孔容积迅速增大，平均孔径逐渐减少，表面分形维数和体积分形维数均增大；650℃后，各参数均表现出相反的变化规律。650℃竹屑热解生物焦具有较好孔隙结构，比表面积可达307.65 m2/g。根据竹屑热解多联产产物分布规律与演变特性，可同时得到具有较高品质的气、液和固三态产物，有利于实现竹屑综合高效利用，为竹屑热解多联产设备的开发与运行提供参考依据。展开更多
Flexible,compact,lightweight and sustainable power sources are indispensable for modern wearable and personal electronics and small-unmanned aerial vehicles(UAVs).Hierarchical honeycomb has the unique merits of compac...Flexible,compact,lightweight and sustainable power sources are indispensable for modern wearable and personal electronics and small-unmanned aerial vehicles(UAVs).Hierarchical honeycomb has the unique merits of compact mesostructures,excellent energy absorption properties and considerable weight to strength ratios.Herein,a honeycomb-inspired triboelectric nanogenerator(h-TENG)is proposed for biomechanical and UAV morphing wing energy harvesting based on contact triboelectrification wavy surface of cellular honeycomb structure.The wavy surface comprises a multilayered thin film structure(combining polyethylene terephthalate,silver nanowires and fluorinated ethylene propylene)fabricated through high-temperature thermoplastic molding and wafer-level bonding process.With superior synchronization of large amounts of energy generation units with honeycomb cells,the manufactured h-TENG prototype produces the maximum instantaneous open-circuit voltage,short-circuit current and output power of 1207 V,68.5μA and 12.4 mW,respectively,corresponding to a remarkable peak power density of 0.275 mW cm^(−3)(or 2.48 mW g^(−1))under hand pressing excitations.Attributed to the excellent elastic property of self-rebounding honeycomb structure,the flexible and transparent h-TENG can be easily pressed,bent and integrated into shoes for real-time insole plantar pressure mapping.The lightweight and compact h-TENG is further installed into a morphing wing of small UAVs for efficiently converting the flapping energy of ailerons into electricity for the first time.This research demonstrates this new conceptualizing single h-TENG device’s versatility and viability for broad-range real-world application scenarios.展开更多
Defect engineering greatly enhances the cat-alytic activity of transition metal semiconductor photocat-alysts.Recently,localized surface defects engineering has been intensively researched,but it still remains challen...Defect engineering greatly enhances the cat-alytic activity of transition metal semiconductor photocat-alysts.Recently,localized surface defects engineering has been intensively researched,but it still remains challenges on how to tilt the balance to the controllable construction of surface defects rather than bulk ones.Here,we report a facile room-temperature solution processing strategy on(001)facet exposed anatase TiO_(2) nanosheets(ATO),in which localized defects are generated on the surface selectivity with high concentration.To achieve the aspect,lithium-ethylenediamine(Li-EDA)treatment is carried out on(001)facet exposed ATO under a mild condition.The optimized sample exhibits outstanding photocatalytic H_(2) production rates of 9.28 mmol·g^(-1)·h^(-1) with loading 0.5 wt%Pt as co-catalyst(AM 1.5),which is nearly 7.5 times higher than that of the pristine ATO.This defect engi-neering strategy of ATO photocatalyst will spark the ideas for the defects engineering and semiconductor photocata-lyst,which is with important application prospect in solar energy conversion,including hydrogen generation and carbon dioxide reduction.展开更多
基金This research is supported by the National Natural Science Foundation of China Grant(Nos.51705429&61801525)the Fundamental Research Funds for the Central Universities,Guangdong Natural Science Funds Grant(2018A030313400)+1 种基金Space Science and Technology Foundation,111 Project No.B13044UK Engineering and Physical Sciences Research Council(EPSRC)for support under grant EP/P018998/1,Newton Mobility Grant(IE161019)through Royal Society.
文摘Flexible,compact,lightweight and sustainable power sources are indispensable for modern wearable and personal electronics and small-unmanned aerial vehicles(UAVs).Hierarchical honeycomb has the unique merits of compact mesostructures,excellent energy absorption properties and considerable weight to strength ratios.Herein,a honeycomb-inspired triboelectric nanogenerator(h-TENG)is proposed for biomechanical and UAV morphing wing energy harvesting based on contact triboelectrification wavy surface of cellular honeycomb structure.The wavy surface comprises a multilayered thin film structure(combining polyethylene terephthalate,silver nanowires and fluorinated ethylene propylene)fabricated through high-temperature thermoplastic molding and wafer-level bonding process.With superior synchronization of large amounts of energy generation units with honeycomb cells,the manufactured h-TENG prototype produces the maximum instantaneous open-circuit voltage,short-circuit current and output power of 1207 V,68.5μA and 12.4 mW,respectively,corresponding to a remarkable peak power density of 0.275 mW cm^(−3)(or 2.48 mW g^(−1))under hand pressing excitations.Attributed to the excellent elastic property of self-rebounding honeycomb structure,the flexible and transparent h-TENG can be easily pressed,bent and integrated into shoes for real-time insole plantar pressure mapping.The lightweight and compact h-TENG is further installed into a morphing wing of small UAVs for efficiently converting the flapping energy of ailerons into electricity for the first time.This research demonstrates this new conceptualizing single h-TENG device’s versatility and viability for broad-range real-world application scenarios.
基金financially supported by the National Natural Science Foundation of China (Nos.21902104 and 21701135)the Natural Science Foundation of Top Talent of Shenzhen Technology University (No.2019108101003)the Foundation for Young Innovative Talents in Higher Education of Guangdong (No.2018KQNCX401)
文摘Defect engineering greatly enhances the cat-alytic activity of transition metal semiconductor photocat-alysts.Recently,localized surface defects engineering has been intensively researched,but it still remains challenges on how to tilt the balance to the controllable construction of surface defects rather than bulk ones.Here,we report a facile room-temperature solution processing strategy on(001)facet exposed anatase TiO_(2) nanosheets(ATO),in which localized defects are generated on the surface selectivity with high concentration.To achieve the aspect,lithium-ethylenediamine(Li-EDA)treatment is carried out on(001)facet exposed ATO under a mild condition.The optimized sample exhibits outstanding photocatalytic H_(2) production rates of 9.28 mmol·g^(-1)·h^(-1) with loading 0.5 wt%Pt as co-catalyst(AM 1.5),which is nearly 7.5 times higher than that of the pristine ATO.This defect engi-neering strategy of ATO photocatalyst will spark the ideas for the defects engineering and semiconductor photocata-lyst,which is with important application prospect in solar energy conversion,including hydrogen generation and carbon dioxide reduction.
