Three different methods (ultrasonic dispersion, hydrothermal method and calcination) were used to prepared g-C ₃N ₄/WO ₃  heterojunctions. Obtained catalysts were characterized with X-ray diffraction (XRD), UVvis spectroscopy, nitrogen adsorption, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and Electrochemical impedance spectroscopy (EIS). The results showed that the interaction between g-C ₃N ₄/WO ₃  and WO ₃ was obviously affected by the preparation methods, resulting in the significant difference in separation rate of photogenerated electrons and holes. The photocatalytic performances were detected in photocatalytic Rhodamine B (RhB) degradation under simulated visible light. The results indicated that activities of g-C ₃N ₄/WO ₃  heterojunction composites were evidently higher than that of single g-C ₃N ₄/WO ₃  or WO ₃ semiconductor, and the heterojunction semiconductor prepared by the hydrothermal method showed the highest photocatalytic activity.

The sulfidation and oxidation reaction of Fe ₂O ₃ and H ₂S in oil tank containing sulfur were simulated under aerobic condition. In order to evaluate the pyrophoric tendency of H ₂S corrosion product, the temperature changes were measured during the oxidation process. The effect of water on pyrophoric tendency of H ₂S corrosion product was investigated. The results showed that water had important influence on the pyrophoric tendency of H ₂S corrosion product. The pyrophoric reactivity was high in the corrosion product when  Fe ₂O ₃ sample contained some water. But the pyrophoric reactivity of H ₂S corrosion product was lower when there was no water or too much water in  Fe ₂O ₃ sample. With the same water containing, the higher the O ₂ concentration in the mixture of sulfidation gas was, the greater the pyrophoric reactivity of H ₂S corrosion product was.