Search

• Co-doped Ag 3 PO 4 nanoparticles were prepared by a simple deposition method. • Co-doped Ag 3 PO 4 photocatalyst exhibits excellent degradation performance. • Introducing Co impurity level promoted the separation and transfer of carriers. • The mutual conversion of Co3+ and Co2+ generated additional ⋅O 2 −. In this study, an efficient Co-doped Ag 3 PO 4 photocatalyst was prepared by the deposition method. Compared with Ag 3 PO 4 , the degradation efficiency of the optimal sample CAP-2 (the mole ratio of Co/Ag was 0.057 %) for MO (20 mgL−1) increased from 53.4 % to 95.0 % within 20 min, and the degradation efficiency for phenol (20 mgL−1) increased from 57.9 % to 91.8 % within 80 min. Moreover, the CAP-2 sample performed excellent mineralization ability and stable recycling capacity. Free radical capture experiments and electron spin resonance (ESR) measurements indicated that holes (h+) and superoxide radicals (⋅O2−) were the main active radicals. Doping Co ions broadened the optical absorption, introduced impurity level to promote the separation of carriers, and generated additional ⋅O2− owing to the mutual conversion of Co3+ and Co2+, thus considerably improving Ag 3 PO 4 photocatalytic performance. This work provides a new reference for doping metal ions modified semiconductor photocatalysts to efficiently degrade organic pollutants. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, δ-Bi2O3/Bi4O7 heterojunction composites were successfully formed through hydrothermal reactions. The special morphology of rod-like Bi4O7 bonded with nanoparticles δ-Bi2O3 was observed by SEM and TEM, and BET results exhibited that the special surface area of the composite was increased slightly. The enhanced photocatalytic activity was mainly attributed to the construction of heterojunctions at the interface. Compared with two single phase samples, δ-Bi2O3/Bi4O7 exhibited much better photocatalytic efficiency in photocatalytic degradation of organic pollutants under visible light excitation. Especially, the composite BO-2 (the addition amount of δ-Bi2O3 was 0.25 mmol) showed the maximum removal rate for RhB (0.07275 min−1), which was 12.92 and 2.53 times that of δ-Bi2O3 and Bi4O7, respectively. Similarly, the composite showed an excellent removal rate (0.01042 min−1) for phenol, which was 13.71 and 1.77 times that of δ-Bi2O3 and Bi4O7, respectively. Further, TOC test confirmed that the mineralization ability of the composite was significantly improved with the successful construction of the heterojunction. Besides, the photocatalytic circulation tests showed the favorable stability of δ-Bi2O3/Bi4O7, and the trapping agent experiment verified the main active substances during photocatalytic, which were h+ and ·O2−. In addition, the electrochemical experiments results showed that the separation and migration ability of carriers was significantly improved due to the successful establishment of heterojunction. Consequently, a probable mechanism for organic contaminants degradation over δ-Bi2O3/Bi4O7 heterojunction was also proposed, which may spur a growth on Bi4O7 based heterojunction photocatalyst. [ABSTRACT FROM AUTHOR]

In this paper, a novel surface-doped Fe-Bi 2 SiO 5 photocatalyst was synthesized by the oil bath method for the first time. Compared with the pure Bi 2 SiO 5 , the degradation rate constants of the FB-2 (the mole ratio of Fe/Bi was 1.7%) were increased by 3.8 and 5 times for Ciprofloxacin (CIP) and Rhodamine B (RhB), respectively. In addition, the results of the total organic carbon (TOC) test manifested that the mineralization capacity of FB-2 for CIP and RhB were increased to 40.7% and 64.7%, respectively. Moreover, the effects of catalyst dosage, initial solution concentration, initial pH and inorganic anions on photocatalytic performance were studied. The cyclic degradation experiments of FB-2 verified the excellent stability of photocatalysts, while active species trapping experiments and electron spin resonance (ESR) tests showed that superoxide radicals and holes played a major role in the degradation process. The paper presented that the photocatalytic activity of Bi-based photocatalysts was improved by a surface modified method, which provided a new idea for further study. [Display omitted] • Novel Fe-surface-doped Bi 2 SiO 5 photocatalyst was obtained by an oil bath method. • The Fe-surface-doped Bi 2 SiO 5 composite presents a flower-like microstructure. • The photocatalyst exhibits an excellent photocatalytic performance for CIP and RhB removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn2+-doped AgBr photocatalysts with enhanced optical properties were prepared. • The photocatalysts exhibited high photocatalytic activity under sunlight irradiation. • The roles of the impurity energy level in the PC process were investigated. • Space charge distribution of photocatalysts before and after doping was studied. • Potential of photocatalysts in practical environment have been further studied. Manganese ion doping engineering, is promising in the field of photocatalysis, but its effect on simple structure semiconductor is not clear. In this work, high-efficiency manganese doped AgBr photocatalysts were manufactured via an ice bath deposition process and were systematically characterized. Under simulated sunlight irradiation, Mn2+ doped AgBr possessed good degradation activity to rhodamine B (RhB) and Ciprofloxacin (CIP). Notably, the optimal sample AM-2 (the mole ratio of Mn element in the whole sample is 0.014 %) can degrade RhB at a reaction rate constant of 0.10334 min-1, which was 7.72 times that of pure AgBr. In light of density functional theory (DFT), the improvement of photocatalytic performance was due to the incorporation of Mn ions that induced lattice strain, affected the charge distribution, and generated an intermediate Mn 3d-Br 2p two-dimensional energy level in the AgBr band gap. Photoelectrochemical experiments verified that Mn2+ doping promoted the separation and transfer of photogenerated carriers and enhanced light absorption. In addition, the practical application ability of photocatalyst was investigated, and a reliable photocatalytic mechanism was proposed. This study may provide enlightening significance for the general application of doping engineering. [ABSTRACT FROM AUTHOR]