Facile Hydrothermal Synthesis of Plasmonic Photocatalyst Ag@Ag Cl and Degradative Photocatalysis under Visible Light Irradiation

We put forward a new approach for the synthesis of Ag@AgCl plasmonic photocatalyst via a hydrothermal-deposition-photoreduction method. The cetylmethylammonium chloride （CTAC） was used alone as both a source of reactants and surfactant. The structure of the prepared photocatalyst was determined by XRD, SEM, EDX and UV-Vis spectroscoscopy. The photocatalytic properties were investigated by degradation of an organic pollutant, Rhodamine B, under visible light irradiation. The results reveal that the experimental conditions have a great effect on the morphology of Ag@AgCl crystals. Ag@AgC1 crystal is cubic and the Ag@AgCl sample which is photoreduced for 40 min exhibits the highest photoactivity, and 80.6 % RhB is degraded after irradiation for 2 hours using this catalyst. The high photocatalytic activity observed is attributed to the surface plasmon resonance effect ofAg nanoparticles.

Ultrasonic-assisted synthesis of plasmonic Z-scheme Ag/AgCl/WO_3-nanoflakes photocatalyst in geothermal water with enhanced visible-light photocatalytic performance

In this study, the Ag/Ag Cl/WO3 plasmonic Z-scheme photocatalysts with different contents of Ag/Ag Cl nanoparticles（NPs） were prepared through a facile ultrasonic precipitation method in geothermal water,wherein the geothermal water served as the chlorine source. Then the photocatalytic activity was investigated by degradation of 4-Aminobenzoic acid（4-ABA） under visible-light irradiation. It was found that the as-prepared 50 wt% Ag/Ag Cl/WO3 photocatalyst showed the highest photocatalytic efficiency with 25.12 and 3.53 times higher than those of pure WO3 and Ag/Ag Cl, respectively. The active species trapping experiments indicated that h＋and ·O2-were key factors in 4-ABA photodegradation process. The possible plasmonic Z-scheme photocatalytic mechanism of photocatalytic reaction for 4-ABA degradation was proposed based on systematical characterizations. We hope this paper could give new ideas for further exploiting geothermal energy to design and fabricate highly efficient visible-light-driven photocatalysts for environmental remediation.

Energy transfer in plasmonic photocatalytic composites

Among the many novel photocatalytic systems developed in very recent years,plasmonic photocatalytic composites possess great potential for use in applications and are one of the most intensively investigated photocatalytic systems owing to their high solar energy utilization efficiency.In these composites,the plasmonic nanoparticles(PNPs)efficiently absorb solar light through localized surface plasmon resonance and convert it into energetic electrons and holes in the nearby semiconductor.This energy transfer from PNPs to semiconductors plays a decisive role in the overall photocatalytic performance.Thus,the underlying physical mechanism is of great scientific and technological importance and is one of the hottest topics in the area of plasmonic photocatalysts.In this review,we examine the very recent advances in understanding the energy transfer process in plasmonic photocatalytic composites,describing both the theoretical basis of this process and experimental demonstrations.The factors that affect the energy transfer efficiencies and how to improve the efficiencies to yield better photocatalytic performance are also discussed.Furthermore,comparisons are made between the various energy transfer processes,emphasizing their limitations/benefits for efficient operation of plasmonic photocatalysts.

Fabrication of Bi-Bi3O4Cl plasmon photocatalysts for removal of aqueous emerging contaminants under visible light

Photocatalytic oxidation of emerging contaminants(ECs) in water has recently gained extensive attentions. In this study, bismuth oxychloride-based plasmon photocatalysts(BiBiOCl) exhibiting high performance were successfully developed by reducing Bion the surface of BiOCl. Consequently, the photocatalysts were used to remove ECs from water.The effects of developmental process and Bi metal plasmon resonance on the photoelectric performances of Bi-BiOCl were investigated through a series of characterizations. The UV-vis diffuse reflection and photoluminescence spectra revealed that the light absorption range of the photocatalyst gradually increased and the electron recombination rate gradually decreased with the introduction of Bi metals. The optimal removal rates of ciprofloxacin and tetrabromobisphenol A by Bi-BiOCl were 93.8% and 96.4%;the respective reaction rate constants were 5.48 and 4.93 times higher than that of BiOCl. The mechanism study indicated that main reactants in the photocatalytic system were ·O-2radicals and photogenerated holes, and the existence of oxygen vacancies and Bi metals promoted electron transfer in photocatalyst. In conclusion, this research produces a novel, green, highly efficient, and stable visible light photocatalyst for the removal of ECs from water.