In this study, photobactericidal films exhibiting excellent antibacterial activity upon irradiation under green light (530–545 nm) were prepared by incorporating erythrosine B (EB) into ethyl cellulose (EC) film. The results of Fourier-transform infrared spectra illustrated that the EB was successfully encapsulated in the films. Additionally, the EC/EB films exhibited a semi-transparent magenta hue with some UV blocking properties. As the amount of EB added to the EC films increased the tensile strength decreased from 22.79 MPa to 9.09 MPa, and the elongation at break increased from 8.20 % to 30.80 %. Under green light irradiation, the EC/EB films showed strong antibacterial activity (> 99 % bacteriostasis rate for Staphylococcus aureus and Escherichia coli ). Research on antibacterial mechanisms implied that the reactive oxygen species generated via photochemical pathways, caused damage to the bacterial cell membrane, leading to the leakage of substances within the bacterial cells and ultimately resulting in the death of the bacteria. Finally, the EC/EB films were applied to the preservation of salmon fillets, and the results showed the EC/EB films could significantly inhibit the growth of spoilage bacteria, thereby extending the shelf life by 2–3 days. Therefore, the prepared photobactericidal films have more potential for application in aquatic products preservation.
A novel electrochemiluminescence (ECL) system consisting of Eosin B (EB) and K 2 S 2 O 8 was studied and found to generate ECL following the oxidation or reduction of Eosin B and K 2 S 2 O 8 . The type of buffer solution, type of co-reactant, pH value, and K 2 S 2 O 8 concentration were optimized through experiments to make the reaction system reach the best value. In addition, we found that Cr 3+ has a great quenching effect on the EB reaction system. Through the comparison of ECL and CV under different conditions, DPV curve, UV spectrum and ECL spectrum experiments, we focused on the quenching mechanism of Cr 3+ on the system and made reasonable guesses. This method demonstrates the potential application value of ECL in the field of environmental monitoring and reveals the potential value of organic molecular ECL luminophores.
Mingcai Yin,Jiangfan Sun,Yixian Li,Yimin Ye,Kaiyue Liang,Yaoting Fan,Zhongjun Li
MoS 2 is a promising catalyst for hydrogen evolution reaction, whereas the inherent defects of limited active sites for H 2 evolution and poor conductivity impede its practical application. Herein, low-cost and available activated carbon (denoted as C) was introduced and MoS 2 /C composite was prepared via a facile one-pot liquid-phased reaction. The MoS 2 /C exhibits an excellent photocatalytic hydrogen evolution activity (872.3 μmol/h) sensitized by Erythrosin B under LED light irradiation, which is about 1.8 times that of pure MoS 2 . Moreover, hydrogen evolution mechanism and reasons for the enhanced performance of MoS 2 /C were proposed based on the results of photoluminescence spectra and photoelectrochemical tests.
Xuqian Wang,Yuanyuan Peng,Tonghui Xie,Yongkui Zhang,Yabo Wang,Huan Yang
Photocatalysis represents an environmental-benign approach for organic pollutant treatment. Herein, a photocatalytic system composed of Ni x P/biocarbon composite as reactive center and erythrosine B (ErB) as sensitizer was constructed for the removal of sulfamethoxazole (SMX) antibiotic under visible light irradiation. Ni x P/biocarbon composites were fabricated via a facile impregnation-pyrolysis approach using baker’s yeast as both phosphorus and carbon precursor. It was found that Ni x P with pure Ni 12 P 5 , almost pure Ni 2 P or mixed crystal phases could be obtained by simply adjusting Ni:P molar ratio in precursor and pyrolysis temperature. Interestingly, the variation of Ni x P crystal phases remarkably affected photocatalytic removal efficiency of SMX. The obtained Ni x P(1:4)− 900 sample with mixed phases of Ni 12 P 5 and Ni 2 P displayed excellent photodegradation performance with 98.71% removal efficiency for SMX ( C 0 = 20 mg L −1 ) in ErB-sensitized photocatalytic system. Moreover, the reusability of Ni x P/biocarbon composite was confirmed by four consecutive runs. The slight loss of activity in recycle study could be fully recovered after thermal regeneration. Further investigation indicated that photo-generated electrons from excited ErB molecules could be transferred to Ni x P/biocarbon, triggering a series of reactions to form various reactive oxygen species (eg., •O 2 − , H 2 O 2 , •OH) for SMX degradation. The better photocatalytic activity of Ni x P mixed crystal phases should be ascribed to its faster electron transfer ability. Overall, this study provides useful guidance in terms of the development of transition metal phosphide and efficient photocatalytic system.
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