Construction of efficient bismuth/boron-based flexible electrode in organic media toward neutral hydrogen evolution

Preparing high-efficient, low-cost and stable catalysts to produce hydrogen in neutral electrolyte is a major challenge due to the sluggish kinetics, low conductivity and complex hydrogen adsorption-desorption process. Here, series...

One-Pot Synthesis of Chlorophyll-Assisted Exfoliated MoS2/WS2 Heterostructures via Liquid-Phase Exfoliation Method for Photocatalytic Hydrogen Production

Developing strategies for producing hydrogen economically and in greener ways is still an unaccomplished goal. Photoelectrochemical (PEC) water splitting using photoelectrodes under neutral electrolyte conditions provides possibly one of the greenest routes to produce hydrogen. Here, we demonstrate that chlorophyll extracts can be used as an efficient exfoliant to exfoliate bulk MoS2 and WS2 to form a thin layer of a MoS2/WS2 heterostructure. Thin films of solution-processed MoS2 and WS2 nanosheets display photocurrent densities of −1 and −5 mA/cm2, respectively, and hydrogen evolution under simulated solar irradiation. The exfoliated WS2 is significantly more efficient than the exfoliated MoS2; however, the MoS2/WS2 heterostructure results in a 2500% increase in photocurrent densities compared to the individual constituents and over 12 h of PEC durability under a neutral electrolyte. Surprisingly, in real seawater, the MoS2/WS2 heterostructure exhibits stable hydrogen production after solar illumination for 12 h. The synthesis method showed, for the first time, how the MoS2/WS2 heterostructure can be used to produce hydrogen effectively. Our findings highlight the prospects for this heterostructure, which could be coupled with various processes towards improving PEC efficiency and applications.

Electrochemical degradation of chloramphenicol using Ti-based SnO2-Sb-Ni electrode

Antibiotic residues may be very harmful in aquatic environments, because of limited treatment efficiency of traditional treatment methods. An electrochemical system with Ti-based SnO2-Sb-Ni anode was developed to degrade a typical antibiotic chloramphenicol (CAP) in water. The electrode was prepared by sol-gel method. The performance of electrode materials, impact factors and dynamic characteristics were evaluated. The Ti-based SnO2-Sb-Ni electrode was compact and uniform by the characterization of SEM and XRD. The electrocatalytic oxidation of CAP was carried out in a single-chamber reactor by using Ti-based SnO2-Sb-Ni electrode. For 100 mg L−1 CAP, the CAP removal ratio of 100% and the TOC removal ratio of 60% were obtained at the current density of 20 mA cm−2 and in neutral electrolyte at 300 min. The kinetic investigation has shown that the electro-oxidation of CAP on Ti-based SnO2-Sb-Ni electrode displayed pseudo first-order kinetic model. Free radical quenching experiments presented that the oxidation of CAP on Ti-based SnO2-Sb-Ni electrode resulted from the synergistic effect of direct oxidation and indirect oxidation (·OH and ·SO4−). Doping Ni on the Ti/SnO2-Sb electrode for CAP degradation was presented in this paper, showing its great application potential in the area of antibiotic and halogenated organic pollutants degradation.