Flow-accelerated corrosion behavior of 13Cr stainless steel in a wet gas environment containing CO_2

This work investigated the flow-accelerated corrosion （FAC） behavior of 13Cr in a wet CO2-containing environment at different flowing gas velocities mid impinging mlgles, with the natural-gas pipeline environment simulated by a self-assembled impingement jet sys- tem. Surface molphology determination, electrochemical measurements, mid hydromechaziics numerical analysis were cmlied out to study the FAC behavior. The results demonstrate that pitting corrosion was the primary mode of corrosion in 13Cr stainless steel. High-flow-rate gas destroyed the passive film mid decreased the pitting potential, resulting in more serious corrosion. The corrosion degree witk various im- pact mlgles showed the following order： 90~ 〉 60~ 〉 45~. The shear force and the electrolyte from the flowing gas were concluded to be the determinm^t factors of FAC, whereas the shear force was the main factor responsible for destroying the passive film.

Preparation of 2D square-like Bi2S3-BiOCl heterostructures with enhanced visible light-driven photocatalytic performance for dye pollutant degradation

A series of Bi2 S3-BiOCI composites with two-dimensional(2 D) square-like structures were prepared via a two-step anion exchange route.X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and diffuse reflectance spectra(DRS)were used to investigate the properties of the as-prepared Bi_2 S_3-BiOCI heterostructures. The coupling of BiOCl and Bi_2 S_3 induced enhanced photoabsorption efficiency and bandgap narrowing. A reactive brilliant red X-3 B dye was used as a contaminant to test the photocatalytic activity of the obtained Bi_2 S_3-BiOCl samples under visible light irradiation. The sample Bi_2 S_3-BiOCl with a mass ratio of 8:4 exhibited the highest photodegradation efficiency, which was six times higher than that of pure BiOCl. In addition, a mechanism for the enhancement of photocatalytic activity is proposed.

Dual Z-scheme Bi_(3)TaO_(7)/Bi_(2)S_(3)/SnS_(2)photocatalyst with high performance for Cr(Ⅵ)reduction and TC degradation under visible light irradiation

Ternary direct dual Z-scheme Bi_(3)T_(a)O_(7)/Bi_(2)S_(3)/SnS_(2) photocatalyst was successfully prepared by hydrothermal method.The composite photocatalysts exhibited high photocatalytic performance on both Cr(Ⅵ)reduction and tetracycline(TC)degradation under the irradiation of visible light.The results manifested that the photogenerated charge transfer efficiency was improved after forming the dual Z-scheme heterojunction.As a result,the composite catalysts exhibited higher photocat-alytic degradation efficiency than the corresponding single samples.The apparent rate constant(k)value of the best sample BBS-3 for TC degradation was 0.0403 min^(-1),which was 40 times,8 times,and 18 times higher than that of single samples.While the k value of BBS-3 for the Cr(Ⅵ)reduction was 0.0249 min^(-1),it was about 23 times,7 times,and 18 times that of single catalysts.Recycle experiments indicated that the BBS-3 had good photocat-alytic stability.Meanwhile,the possible mechanism on Cr(Ⅵ)reduction and TC degradation was proposed based on the experimental results.