Lisong Xiao

Hydrothermal synthesis of porous rh-In2O3 nanostructures with visible-light-driven photocatalytic degradation of tetracycline

In this paper, well-defined 3D flower-like porous rhombohedral In2O3 (rh-In2O3) nanostructures were successfully synthesized via the hydrothermal method combined with post-thermal treatments. Interestingly, 3D flower-like c-In2O3 nanostructures could also be obtained by simply adjusting the annealing temperature according to this reaction route. The possible growth mechanism of the obtained flower-like In2O3 nanostructures was proposed based on a series of contrasting experimental observations depending on the different reaction conditions as well as our understanding. Whats more, we also investigated the photocatalytic activities of bulk In2O3, 3D flower-like rh-In2O3, and c-In2O3 nanostructures for the degradation of tetracycline (TC) under visible light. Photocatalytic degradation results indicated that 3D flower-like porous rh-In2O3 nanostructures exhibited the highest photocatalytic activities. The possible photocatalytic mechanism for the degradation of TC in 3D flower-like porous rh-In2O3 nanostructures was also discussed.

Solvothermal synthesis and visible light-driven photocatalytic degradation for tetracycline of Fe-doped SrTiO3

In this paper, Fe-doped SrTiO3 (FSTO) photocatalysts were successfully prepared via a facile solvothermal method, and their photocatalytic activities for degrading tetracycline (TC) under visible light irradiation were examined. It was found that doping Fe3+ into the lattice of SrTiO3 resulted in the formation of new absorption bands in the visible light region, and the energy band gap decreased from 3.2 eV to 2.6 eV with Fe3+ doping amounts of 0 to 5 wt%. The photocatalytic experimental results indicated that the as-prepared FSTO photocatalysts generate an extremely high enhancement in the TC degradation ratio compared to the pure SrTiO3 under visible light irradiation. In particular, the FSTO sample doped with 3% Fe exhibited the highest TC degradation ratio (71.6%) in 80 min, which is mainly attributed to the narrowed gap generated by the appropriate level of Fe3+ doping. This work suggests that this doping method should be applicable for exploiting other efficient visible light-driven photocatalysts with wide band gap semiconductors.

Visible-light-drived high photocatalytic activities of Cu/g-C3N4 photocatalysts for hydrogen production

Cu/g-C3N4 photocatalysts have been synthesized using a facile method. The composition and morphology of the prepared samples were characterized by a variety of analytical methods. The results indicate that the Cu nanoparticles were uniformly loaded onto the surface of g-C3N4. In addition, photocatalytic activity experiments were carried out by investigating H2 production under visible light irradiation. The results reveal that the composites exhibited excellent performance for H2 evolution in the absence of a cocatalyst, which demonstrates that Cu nanoparticles could trap photogenerated electrons and act as a cocatalyst effectively. Thus, it was effective in transferring the interfacial photogenerated charge carriers and efficiently enhanced the photocatalytic activity.

Graphene oxide-assisted synthesis and photocatalytic hydrogen production of mix-phase titanium dioxide (TiO2) nanosheets

Novel mix-phase TiO2 nanosheets were successfully synthesized by a facile sol–gel method using graphene oxide (GO) as the sacrifice template for the first time. The SEM, TEM and AFM images revealed that the thickness of mix-phase TiO2 nanosheets was ca. 66 nm, and the TiO2 nanosheets were in a polycrystalline phase and made up of nanoparticles with the diameters of 15–25 nm. In addition, we observed that the proportion of rutile and anatase changed with the amount of tetrabutyltitanate (TBT). The results showed that the sample with 4 mL tetrabutyltitanate (TBT-4) exhibited the highest hydrogen production rate (339 μmol h−1) in all samples, which was 47% higher compared to the bulk sample. It was attributed mainly to the surface phase junction of anatase and rutile and the special morphology of the samples.

Facile synthesis of BiOI/CdWO4 p–n junctions: enhanced photocatalytic activities and photoelectrochemistry

In this work, a series of novel BiOI/CdWO4 p–n junction photocatalysts were successfully fabricated via a facile ultrasonic and stirring process. The photodegradation tests showed that the BiOI/CdWO4 p–n junction photocatalysts show enhanced efficiencies compared to pure BiOI and CdWO4. The best photocatalytic performance was obtained for the BC-2.0 sample, and the as prepared samples were studied by XRD, TEM, HRTEM, XPS, UV-vis DRS and photoluminescence (PL) spectroscopy. This enhancement may be predominantly attributed to the improvement of the photogenerated electron–hole separation and migration efficiency of the synergy impact between BiOI and CdWO4. The efficient separation of electron–hole pairs because of the synergy impact between BiOI and CdWO4. Radical scavenger experiments and ESR indicated that holes (h+) and superoxide radicals (˙O2−) were the main active species in the photocatalytic process.

Fabrication and excellent visible-light-driven photodegradation activity for antibiotics of SrTiO3 nanocube coated CdS microsphere heterojunctions

Extending the light absorption range and facilitating the separation of photoinduced carriers are effective strategies in the process of improving photocatalysis. An effective method is to construct a heterostructure. In this work, a new heterojunction, CdS/SrTiO3, was synthesized via a two step hydrothermal route and designed to decontaminate hazardous wastewater containing antibiotics under visible light irradiation. Specially, the efficient photocatalytic performance of the composites could be ascribed to the enhancement of visible light absorption efficiency and the efficient separation of the photoexcited carriers originating from the heterointerface. Furthermore, a plausible photocatalytic mechanism has been discussed in detail based on trap experiments and ESR analysis results. The CdS/SrTiO3 heterojunction has potential to be applied for purifying antibiotic pollutants in environmental wastewater because of its high efficiency and stability.

Carbon quantum dot decorated hollow In2S3 microspheres with efficient visible-light-driven photocatalytic activities

Carbon quantum dot (CQDs) decorated hollow In2S3 microspheres were firstly synthesized by a facile hydrothermal method. CQDs with an average size of 5 nm were attached on the surfaces of hollow In2S3 microspheres. The photocatalytic activities of the as-prepared samples were investigated by the photocatalytic degradation of methyl orange under visible light, and the 3 wt% CQDs/In2S3 sample presented the most efficient photocatalytic activity which was almost 3 times the pure In2S3 sample. On the basis of the active species trapping experiment and ESR analysis, holes and superoxide radicals were proved to be the main active species in the photocatalytic degradation process, and a possible reaction mechanism was proposed.