Search

• The Am-SnO 2 @P-C powders are synthesized through phase separation and heat treatment. • The differences of amorphous and crystalline SnO 2 based electrodes are investigated. • The porous carbon matrix will improve the structural stability of electrodes. • The Am-SnO 2 @P-C electrode exhibits excellent cycling stability and rate capability. Amorphous SnO 2 nanoparticles embedded into a three-dimensional porous carbon matrix labeled as Am-SnO 2 @P-C are precisely customized through a phase separation process of tin salts and polyacrylonitrile/polyvinylpyrrolidone/ N, N -dimethylformamide polymer mixed solution with the presence of deionized water and combining with heat treatments. The targeted composite powders are characterized by X-ray diffraction, X-ray photoelectron spectroscope, transmission electron microscope, and scanning electron microscope, in which amorphous SnO 2 nanoparticles with ultrafine diameters are uniformly distributed across the three-dimensional porous carbon matrix. The Am-SnO 2 @P-C composite electrode can deliver an initial discharge and charge specific capacity of 1557.6 and 1194.4 mAh/g with an initial coulombic efficiency of 76.7 % at 100 mA/g, and the discharge specific capacity can be retained at 886.4 mAh/g after 200 cycles. Moreover, the Am-SnO 2 @P-C composite electrode also exhibits great rate capability, in which the electrode can deliver a reversible capacity of 581.1 mAh/g at the current density as high as 1.0 A/g with a capacity retention of 92.8 % after 500 cycles. Furthermore, the kinetics investigations of pseudocapacitive contributions and electrochemical impedance spectroscopy on the as-prepared composite electrodes demonstrate the fast electrochemical kinetics of the Am-SnO 2 @P-C electrode due to the synergistic effect of the ultrafine size of amorphous SnO 2 nanoparticles and the porous carbon matrix. Those findings and understandings of the SnO 2 based electrodes may offer some a prospective strategy of the metal-oxide based anodes for lithium-ion batteries in the field of energy storages. [Display omitted]. [ABSTRACT FROM AUTHOR]

TiO 2 nanorods decorated with CdS and Ag0 were prepared and anchored on to a fluorine doped tin oxide (FTO) electrode in order to investigate the photoelectrochemical (PEC) oxidation of nitrobenzene (NB) coupled with simultaneous reduction of water to produce molecular hydrogen (H 2). The modified TiO 2 nanorods (TiO 2 -NRs) prepared for 4 h have regular nanoroads with high superficial area and Ag nanoparticles loaded on the surface of nanoroads covered with CdS film uniformly. The nano-composite TiO 2 -NRs with photochemically active up to 700 nm with coupled photoconversion efficiencies for NB degradation and H 2 production as high as 4.4%. The surface plasmon resonance (SPR) effect of Ag not only excited the photo-generated electron of Ag nanoparticles, but also promoted the electron transfer from CdS to TiO 2 -NRs. NB as a role of electron donor, reacts with hole to improve the efficiency of H 2 production. The heterostructure electrode for solar energy conversion had an important significance for solving environmental pollution and energy crisis. Image 1 • TiO 2 nanorods decorated with CdS and Ag0 were prepared and anchored on to a FTO electrode. • Simultaneous oxidation of nitrobenzene coupled with reduction of water to produced H 2. • Ag particles loaded on the surface of TiO 2 nanoroads covered with CdS film uniformly. • Photoconversion efficiencies for nitrobenzene degradation and H 2 production as high as 4.4%. • The heterostructure of CdS/Ag/TiO 2 -NRs electrode has solar energy conversion in PEC system. [ABSTRACT FROM AUTHOR]