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It is highly important to develop efficient and cheap photocatalysts for hydrogen production. Herein, a series of p–n heterojunction Mn 0.5 Cd 0.5 S/CuCo 2 S 4 has been successfully synthesized for the first time by the hydrothermal impregnation method. Mn 0.5 Cd 0.5 S/CuCo 2 S 4 loading with 12 wt % CuCo 2 S 4 shows the highest H 2 evolution rate of 15.74 mmol h –1 g –1 under visible light (λ ≥ 420 nm) irradiation, which is about 3.15 and 15.28 times higher than that of bare Mn 0.5 Cd 0.5 S (4.99 mmol h –1 g –1 ) and CuCo 2 S 4 (1.03 mmol h –1 g –1 ), respectively. In addition, it shows a relatively good stability during the five recycle tests, with about 20% loss of reaction rate compared to that of the first cycle. The superior photocatalytic performance is attributed to the effective separation and transfer of photogenerated charge carriers because of the formation of the p–n junction. The samples are systematically characterized by X-ray diffraction, ultraviolet–visible (UV–vis), diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, X-ray photoelectron spectroscopy, photoluminescence, EIS, and so on. UV–vis and EIS show that CuCo 2 S 4 can effectively improve the visible light response of Mn 0.5 Cd 0.5 S/CuCo 2 S 4 and promote the electron transfer from CuCo 2 S 4 to the conduction band of Mn 0.5 Cd 0.5 S, so as to improve the photocatalytic efficiency. This study reveals that the p–n heterojunction Mn 0.5 Cd 0.5 S/CuCo 2 S 4 is a promising photocatalyst to explore the photocatalysts without noble metals.

To improve the catalytic combustion performance of toluene, a series of Co–CeO x monolith catalysts were synthesized by the citric acid sol–gel method. The results showed that the introduction of Co to CeO2 by the citric acid sol–gel method can effectively improve the catalytic performance in the reaction of toluene oxidation. Co1Ce2O x with the molar ratio of Co to Ce being 1:2 showed optimal activity and reached T 90 at 275 °C. In addition, Co1Ce2O x exhibited excellent adaptability under the various space velocities and concentration conditions, and it also revealed good thermal stability. The physical and chemical properties of the as-prepared catalysts were investigated by various technologies. The results showed that the combination of Co and Ce could induce a strong interaction between Co3O4 nanoparticles and CeO2 nanoparticles, exerting a synergistic promoting effect on the formation of oxygen vacancies, which subsequently enhances the active oxygen mobility and improves the catalytic oxidation performance. The possible mechanism of enhanced catalytic performance of Co1Ce2O x was also proposed.

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Magnetorheological elastomers are one kind of smart materials which consist of matrix materials and magnetic particles. The mechanical properties of magnetorheological elastomers were controllable under an external magnetic field. Applications of magnetorheological elastomers are limited as a result of their poor magnetorheological effect and mechanical performance, so enhancing the magnetorheological effect of them is critical for their application. Styrene-ethylene-butylene-styrene based thermoplastic elastomer was added to natural rubber to fabricate hybrid matrix–based magnetorheological elastomers. Zero modulus of magnetorheological elastomers increased from 0.50 to 0.64 MPa and magnetorheological effect increased from 28.00% to 43.75% with the addition of styrene-ethylene-butylene-styrene based thermoplastic elastomer. The contact angle of carbonyl iron particles with the matrix showed that styrene-ethylene-butylene-styrene based thermoplastic elastomer can improve the compatibility of carbonyl iron particles with the matrix. Fourier-transform infrared spectroscopy analysis has been carried out to investigate the internal structure of hybrid matrix–based magnetorheological elastomers.