Search

Ce/N co-doped TiO2/NiFe2O4/diatomite (CN-TND) hybrid catalyst was prepared via sol-gel method. This ternary composite combined the advantages of three components: adsorption capability of diatomite (Dt), visible-light-driven photoactivity of Ce/N co-doped TiO2 (Ce/N-TiO2), and magnetic recyclability of ferrite NiFe2O4. The physicochemical properties of CN-TND were characterized by various analytical methods. The visible-light-driven photoactivity of CN-TND was investigated by the degradation of tetracycline (TC) and disinfection of Escherichia coli (E. coli) under visible light irradiation, and the optimal amount of Ce dopant was determined. In addition, the kinetic data of the degradation process were obtained, and the mechanism of this process was proposed. Different scavengers detected the active species involved during the degradation process. CN-TND exhibited ferromagnetism, thus it could be simply separated from the reactor by an external magnet. The reusability test proved its excellent photocatalytic stability and recyclability. We consider it suitable for the application of wastewater treatment.

By molten salt electrolysis combined with aqueous electrodeposition, the composite LaNi 5 /Ni–S film with high stability and hydrogen evolution reaction (HER) activity was obtained. LaNi 5 film was prepared by galvanostatic electrolysis at 100 mA cm −2 under 1273 K. The results showed that the composite LaNi 5 /Ni–S film ( η 150 = 75 mV, 353 K) could absorb large amount of H atoms, which not only increase its electrochemical activity, but also could be oxidized and avoid the dissolution of the Ni–S film under the state of open-circuit effectively and prolong the lifetime of the cathode.

Using an orthogonal design, i.e. the LaCl 3 concentration, the current density and the pH value as the factors, Ni–S(La) alloy was obtained through electrodeposition in a modified Watts bath by adding thiourea (TU) and LaCl 3 into the bath. The structure and morphology were determined by XRD and SEM. The electrochemical properties, including the hydrogen evolution overvoltages η (h.o.v.), the Tafel slope b , the exchange current density i 0 and the activation energy Δ H * of an amorphous Ni–S(La) cathode were measured. The effect of heat treatment under various temperatures on its structure and electrochemical properties were determined. The results indicate that the structure of Ni–S(La) alloy obtained under the optimum conditions is amorphous and it shows much higher electrochemical activity than other electrodes including the amorphous Ni–S electrode due to the higher sulfur content in such an electrode. Heat treatment is harmful to its electrochemical activity.