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In this study, a series of CuO/CdS composites were synthesized by thermal oxidation and successive ionic layer adsorption and reaction (SILAR). The as-prepared CuO/CdS composites were investigated by x-ray diffraction (XRD), field emission high-resolution scanning electron microscopy (FESEM) and energy-dispersive spectrometry. Their photocatalytic activity was investigated by monitoring the degradation of methylene blue (MB) under ultraviolet and visible light irradiation. The XRD pattern indicated that the precursor was cubic-phase CuO and Cu2O. FESEM results indicate that changes in annealing time and temperature have an effect on morphology, but the nanowire structures are preserved. The growth mechanism of the CuO nanowires is discussed in detail. Furthermore, the photocatalytic degradation rate of the MB, determined using an ultraviolet-visible spectrophotometer (UV-vis, UV-2600, Shimadzu), indicates that CdS can significantly improve the absorption of visible light from the sun. [ABSTRACT FROM AUTHOR]

In this paper we prepared titania nanotubes which was doped with erbium ions in ethylene glycol organic electrolyte through ions doping method. We found that the unit cell's parameters of the titania nanotubes increased when the titania nanotubes was doped with erbium ions. The Er 3+ doped titania nanotubes has a strong absorption ability of infrared light, and the doping Er 3+ has a characteristic peak when the wave number is 2341 cm −1 . When the concentration of the doping Er 3+ is 2.61 mmol/L, the titania nanotubes’ photo-degradation rate of the methylene blue can be reached to 95.2% which is larger than the titania nanotubes without doping with erbium ions. So, the titania nanotubes doped with Er 3+ is extremely suitable for using as photocatalytic materials. [ABSTRACT FROM AUTHOR]

Monoclinic nanostructured CuO films with star-like morphology on indium tin oxide (ITO)-coated glass substrates were successfully synthesized by electrodeposition method in acidic solution with the pH of 5.7. The as-synthesized films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis. The influence of different electrodeposition parameters and annealing temperature on the growth of CuO films were investigated. The results showed that the nanostructured CuO film was well-crystallized and electrodeposition voltage is the main factor to control its morphology. Moreover, good photocatalytic activity was exhibited and photo-degradation rate to methylene blue can reach 95%. Its optical energy band gap is 3.3 eV. The plausible growth mechanism for the formation of CuO film with star-like structure is also proposed for the first time. [ABSTRACT FROM AUTHOR]

Novel self-assembled BiVO 4 samples with red blood cell-like shape and flower-like microsphere were successfully synthesized via a facile solvothermal approach by using Na 2 CO 3 or NH 3 ·H 2 O as the pH controlling agent and citric acid as the chelating agent. The photocatalytic activity was evaluated by the photocatalytic degradation of methylene blue (MB) under visible light irradiation. The results showed that both the citric acid and pH controlling agent had great influences on the morphologies of the samples. Besides, the relationship between the morphology and photocatalytic activity was studied in detail. Benefiting from the unique morphology, the prepared BiVO 4 samples exhibited excellent photocatalytic activities for the degradation of MB dye under visible light irradiation. [ABSTRACT FROM AUTHOR]

Samples of biochar-coupled g-C 3 N 5 /C have been prepared using 3-amino-1,2,4-triazole and peanut oil as precursors to increase the specific surface area of g-C 3 N 5. The results showed that the specific surface area of g-C 3 N 5 /C-1.0 reached 44.7 m2 g−1, and the C/N ratio increased from 0.56 to 1.48. The weakness of its photoluminescence (PL) peak confirmed that g-C 3 N 5 /C-1.0 had the best separation of photogenerated electrons and holes. Furthermore, the fluorescence lifetime of g-C 3 N 5 /C-1.0 is extended to 6.4 ns, compared to 2.9 ns for g-C 3 N 5. Therefore, g-C 3 N 5 /C-1.0 displays superior photocatalytic activity to that of pure g-C 3 N 5 under visible-light irradiation. This is because the large specific surface area leads to increased absorption of visible light and efficient separation of electron–hole pairs. The hydrogen evolution rate of g-C 3 N 5 /C-1.0 is 303.3 μmol g−1 h−1 (cf. 67.5 μmol g−1 h−1 for g-C 3 N 5), and the photodegradation efficiency of rhodamine B (RhB) is as high as 93.7% (cf. 26.1% for g-C 3 N 5). Sample g-C 3 N 5 /C-1.0 also maintained outstanding photocatalytic stability after four cycles. Radical scavenger experiments and ESR tests have shown •O 2 − to be the main reactive species responsible for RhB degradation under visible light. • Biochar-doped g-C 3 N 5 was synthesized by one-step method with peanut oil as biochar source. • Biochar-doped g-C 3 N 5 can improve the specific surface area and light absorption ability. • g-C 3 N 5 /C-1.0 exhibited H 2 evolution of 303.3 μmol g−1 h−1, which was 4.5 times than that of pure g-C 3 N 5. • The photodegradation to rhodamine B of g-C 3 N 5 /C-1.0 can reach 93.7% after 150 min. • The g-C 3 N 5 /C-1.0 has good photocatalytic activity and chemical stability. [ABSTRACT FROM AUTHOR]

Hierarchically structured m -BiVO 4 samples with different morphologies have been synthesized via a template-free solvothermal route by adjusting the pH value of the precursor solution. The effects of pH value on structure, morphology and photocatalytic activity were investigated. The results showed that the pH value played a great influence not only on the formation of the hierarchical structures with different morphologies, but also on the preferential crystal growth of the BiVO 4 oriented along {040} facets. The pinwheel-like sample with the highest relative intensities of the diffraction peaks I 040 / I –121 exhibited the best photocatalytic activity for the photodegradation of MB under visible light irradiation. According to the Ostwald ripening process, a possible oriented aggregation mechanism was proposed. [ABSTRACT FROM AUTHOR]