g-C_(3)N_(4) emerges as a star 2D photocatalyst due to its unique layered structure,suitable band structure and low cost.However,its photocatalytic application is limited by the fast charge recombination and low photo...g-C_(3)N_(4) emerges as a star 2D photocatalyst due to its unique layered structure,suitable band structure and low cost.However,its photocatalytic application is limited by the fast charge recombination and low photoabsorption.Rationally designing g-C_(3)N_(4)-based heterojunction is promising for improving photocatalytic activity.Besides,g-C_(3)N_(4) exhibits great potentials in electrochemical energy storage.In view of the excellent performance of typical transition metal oxides(TMOs)in photocatalysis and energy storage,this review summarized the advances of TMOs/g-C_(3)N_(4) heterojunctions in the above two areas.Firstly,we introduce several typical TMOs based on their crystal structures and band structures.Then,we summarize different kinds of TMOs/g-C_(3)N_(4) heterojunctions,including type Ⅰ/Ⅱ heterojunction,Z-scheme,p-n junction and Schottky junction,with diverse photocatalytic applications(pollutant degradation,water splitting,CO_(2) reduction and N_(2) fixation)and supercapacitive energy storage.Finally,some promising strategies for improving the performance of TMOs/g-C_(3)N_(4) were proposed.Particularly,the exploration of photocatalysis-assisted supercapacitors was discussed.展开更多
An asymmetrical supercapacitor (ASC), comprising reduced graphene oxide (rGO)-encapsulated nickel phosphite hollow microspheres (NPOH-0.5@rGO) as positive electrode, and porous nitrogen/sulfur co-doped rGO aerog...An asymmetrical supercapacitor (ASC), comprising reduced graphene oxide (rGO)-encapsulated nickel phosphite hollow microspheres (NPOH-0.5@rGO) as positive electrode, and porous nitrogen/sulfur co-doped rGO aerogel (NS-3D rGO) as negative electrode has been prepared. The NPOH-0.5@rGO electrode combines the advantages of the NPOH hollow microspheres and the conductive rGO layers giving rise to a large specific capacitance, high cycling reversibility, and excellent rate performance. The NS-3D rGO electrode with abundant porosity and active sites promotes electrolyte infiltration and broadens the working voltage range. The ASC (NPOH-0.5@rGO//NS-3D rGO) shows a maximum voltage of up to 1.4 V, outstanding cycling ability (capacitance retention of 95.5% after 10,000 cycles), and excellent rate capability (capacitance retention of 77% as the current density is increased ten times). The ASC can light up an light-emitting diodes (LED) for more than 20 min after charging for 20 s. The fabrication technique and device architecture can be extended to other active oxide and carbon-based materials for next-generation high-performance electrochemical storage devices.展开更多
Red phosphorus-carbon nanotube (P@CNT) composites were synthesized as anodes for advanced lithium ion batteries via a facile solution-based method at room temperature. In these composites, the entangled P@CNT nanost...Red phosphorus-carbon nanotube (P@CNT) composites were synthesized as anodes for advanced lithium ion batteries via a facile solution-based method at room temperature. In these composites, the entangled P@CNT nanostructure reduced the aggregation of both components and allowed their complete utilization in a synergetic manner. The highly conductive and porous CNT framework, along with the nanoscale red P particles intimately anchored on the CNT surface, conferred the composite with excellent ion/electron transport properties. Volume expansion within the red P particles was mitigated by their amorphous and nanoscale features, which can be well buffered by the soft CNTs, therefore maintaining an integrated electrode structure during cycling. When used as an anode in lithium ion batteries, the composite exhibited a reversible capacity of 960 mAh·g^-1 (based on the overall weight of the composite) after 120 cycles at 200 mA·g^-1. The composite also delivered excellent high-rate capability with capacities of 886, 847, and 784 mAh·g^-1 at current densities of 2,000, 4,000, and 10,000 mA·g^-1 respectively, which reveals its potential as a high performance anode for lithium ion batteries.展开更多
基金financially supported by the National Natural Science Foundation (No.52072347, 51972288, 51672258 and 51572246)the Fundamental Research Funds for the Central Universities (No. 2652019144 and 2652018287)+1 种基金the financial supports from the Science and Technology Program of Guangdong Province (2019A050510012)Shenzhen Science, Technology and Innovation Commission (SGDX2019081623240364).
文摘g-C_(3)N_(4) emerges as a star 2D photocatalyst due to its unique layered structure,suitable band structure and low cost.However,its photocatalytic application is limited by the fast charge recombination and low photoabsorption.Rationally designing g-C_(3)N_(4)-based heterojunction is promising for improving photocatalytic activity.Besides,g-C_(3)N_(4) exhibits great potentials in electrochemical energy storage.In view of the excellent performance of typical transition metal oxides(TMOs)in photocatalysis and energy storage,this review summarized the advances of TMOs/g-C_(3)N_(4) heterojunctions in the above two areas.Firstly,we introduce several typical TMOs based on their crystal structures and band structures.Then,we summarize different kinds of TMOs/g-C_(3)N_(4) heterojunctions,including type Ⅰ/Ⅱ heterojunction,Z-scheme,p-n junction and Schottky junction,with diverse photocatalytic applications(pollutant degradation,water splitting,CO_(2) reduction and N_(2) fixation)and supercapacitive energy storage.Finally,some promising strategies for improving the performance of TMOs/g-C_(3)N_(4) were proposed.Particularly,the exploration of photocatalysis-assisted supercapacitors was discussed.
基金This work was jointly supported by the National Natural Science Foundation of China (No. 51572246), Fundamental Research Funds for the Central Universi- ties (Nos. 53200859565, 53200859500 and 2652015425), as well as City University of Hong Kong Applied Research Grant (ARG) (No. 9667122) and Strategic Research Grant (SRG) (No. 7004644).
文摘An asymmetrical supercapacitor (ASC), comprising reduced graphene oxide (rGO)-encapsulated nickel phosphite hollow microspheres (NPOH-0.5@rGO) as positive electrode, and porous nitrogen/sulfur co-doped rGO aerogel (NS-3D rGO) as negative electrode has been prepared. The NPOH-0.5@rGO electrode combines the advantages of the NPOH hollow microspheres and the conductive rGO layers giving rise to a large specific capacitance, high cycling reversibility, and excellent rate performance. The NS-3D rGO electrode with abundant porosity and active sites promotes electrolyte infiltration and broadens the working voltage range. The ASC (NPOH-0.5@rGO//NS-3D rGO) shows a maximum voltage of up to 1.4 V, outstanding cycling ability (capacitance retention of 95.5% after 10,000 cycles), and excellent rate capability (capacitance retention of 77% as the current density is increased ten times). The ASC can light up an light-emitting diodes (LED) for more than 20 min after charging for 20 s. The fabrication technique and device architecture can be extended to other active oxide and carbon-based materials for next-generation high-performance electrochemical storage devices.
基金This work was supported by the Fundamental Research Funds for the Central Universities of China (No. 2652015425) and the National Natural Science Foundation of China (No. 51572246).
文摘Red phosphorus-carbon nanotube (P@CNT) composites were synthesized as anodes for advanced lithium ion batteries via a facile solution-based method at room temperature. In these composites, the entangled P@CNT nanostructure reduced the aggregation of both components and allowed their complete utilization in a synergetic manner. The highly conductive and porous CNT framework, along with the nanoscale red P particles intimately anchored on the CNT surface, conferred the composite with excellent ion/electron transport properties. Volume expansion within the red P particles was mitigated by their amorphous and nanoscale features, which can be well buffered by the soft CNTs, therefore maintaining an integrated electrode structure during cycling. When used as an anode in lithium ion batteries, the composite exhibited a reversible capacity of 960 mAh·g^-1 (based on the overall weight of the composite) after 120 cycles at 200 mA·g^-1. The composite also delivered excellent high-rate capability with capacities of 886, 847, and 784 mAh·g^-1 at current densities of 2,000, 4,000, and 10,000 mA·g^-1 respectively, which reveals its potential as a high performance anode for lithium ion batteries.