Two assemblies, porphyrin powder/ITO and porphyrin film/ITO, were built by a facile method. The time-resolved photovoltage technique was utilized to prove the behaviour of photo-induced charges in the two assemblies. The photovoltage results show that the porphyrin film/ITO assembly displays a reversal polarity response, which is different from the response of porphyrin powder/ITO. This phenomenon is due to the effect of a built-in field on photo-induced charge behaviour at the porphyrin film/ITO interface. This result is beneficial for the development of a measuring method for detecting heterojunction interface formation and understanding the photoelectric process in photoelectric materials and devices.

A crystal-facet-induced formation method has been developed for the fabrication of graphitized carbon nanosheets (CNS) embedded with ultrafine SnO2 nanocrystals grown in situ upon calcination under a N2 atmosphere. The obtained SnO2–CNS composite exhibits superior electrochemical performance when used as the anode material for lithium-ion batteries. Cycled at high current densities of 0.5, 1.0 and 10.0 A g−1 for 50 cycles, the composite material delivers large discharge capacities of 826, 728, and 400 mA h g−1, respectively. The graphitized carbon nanosheets facilitate both ion and electron transportation and act as an efficient buffer to accommodate the volume changes generated upon Li-ion insertion–extraction. The ultrafine SnO2 nanocrystals significantly shorten the diffusion distances of the lithium ions and also provide a large contact area for the interface reaction between the anode material and lithium-ions during lithiation or delithiation, leading to a remarkably high specific capacity and good cycling stability.

Sn/SnO nanoparticles are incorporated in crumpled nitrogen-doped graphene nanosheets by a simple melting diffusion method. The resulting composite exhibits large specific capacity, excellent cycling stability and high rate capability as an anode for lithium-ion batteries.

A series of Eu3+-incorporated ETS-10 samples were successfully prepared based on the traditional ion exchange method. The relationship between photogenerated charge behaviors and luminescent properties has been investigated in detail. It has been demonstrated that as a result of the charge transfer from the titanate quantum wires to Eu3+ crystal field states, the host matrix ETS-10 functions as the sensitizer of Eu3+ to enhance the red luminescence, while Eu3+ cations contribute to the recombination of photogenerated charges. The behavior of photogenerated charges has significant impact on the luminescent properties of Eu3+-incorporated ETS-10 materials.

The photovoltaic properties of nanoporous TiO2 film treated with Al3+ ions have been investigated by the spectral and transient photovoltage (PV) technique. The performances of the dye-sensitized solar cells (DSSCs) with different amounts of aluminum oxide were compared. The results showed that with increased amount of aluminum oxide, the spectral PV responses blue shift (with the exception of the 0.1 wt%) and the time of the transient PV maximum increase. The performances of the corresponding cells were improved. These results indicated the dependence of the DSSCs performances on the charge dynamics in the corresponding nanoporous TiO2 film.

Two assemblies, porphyrin powder/ITO and porphyrin film/ITO, were built by a facile method. The time-resolved photovoltage technique was utilized to prove the behaviour of photo-induced charges in the two assemblies. The photovoltage results show that the porphyrin film/ITO assembly displays a reversal polarity response, which is different from the response of porphyrin powder/ITO. This phenomenon is due to the effect of a built-in field on photo-induced charge behaviour at the porphyrin film/ITO interface. This result is beneficial for the development of a measuring method for detecting heterojunction interface formation and understanding the photoelectric process in photoelectric materials and devices.

Carbon-based supercapacitors with high power densities suffer from relatively low energy densities. Nitrogen-doped hierarchical micro/mesoporous carbon nets were successfully fabricated via supramolecular assemblies of block copolymer P123 with the assistance of dicyandiamide and TiO2. The as-obtained carbon nets have a large specific surface area of approximately 2144 m2 g−1, high-level nitrogen doping with a nitrogen content of approximately 8.25 wt%, and a hierarchical porous network composed of micropores and mesopores. The hierarchical porous carbon nets exhibit high specific capacitance (537.3 F g−1 and 306.3 F cm−3 at 0.5 A g−1 in a 0.5 M H2SO4 electrolyte) and outstanding cycling stability (approximately 98.8% of their capacitance was retained after 10000 cycles at 5 A g−1). The symmetric supercapacitor based on these hierarchical porous carbon nets could deliver a maximum energy density up to 22.6 W h kg−1. The improved electrochemical performance of these carbon nets stems from both high surface area and the hierarchical micro/mesoporous structure, which provides an accessible pathway for electrolyte transport. In addition, the incorporation of nitrogen dopants into the carbon was intended to further enhance the capacitance performance. This research provides a facile and effective method to obtain micro/mesoporous carbon with a high surface area and doping level of heteroatoms for high-performance supercapacitors.

Sn/SnO nanoparticles are incorporated in crumpled nitrogen-doped graphene nanosheets by a simple melting diffusion method. The resulting composite exhibits large specific capacity, excellent cycling stability and high rate capability as an anode for lithium-ion batteries.

A crystal-facet-induced formation method has been developed for the fabrication of graphitized carbon nanosheets (CNS) embedded with ultrafine SnO2 nanocrystals grown in situ upon calcination under a N2 atmosphere. The obtained SnO2–CNS composite exhibits superior electrochemical performance when used as the anode material for lithium-ion batteries. Cycled at high current densities of 0.5, 1.0 and 10.0 A g−1 for 50 cycles, the composite material delivers large discharge capacities of 826, 728, and 400 mA h g−1, respectively. The graphitized carbon nanosheets facilitate both ion and electron transportation and act as an efficient buffer to accommodate the volume changes generated upon Li-ion insertion–extraction. The ultrafine SnO2 nanocrystals significantly shorten the diffusion distances of the lithium ions and also provide a large contact area for the interface reaction between the anode material and lithium-ions during lithiation or delithiation, leading to a remarkably high specific capacity and good cycling stability.