Pan CHEN,Jia-yan LIU,Ji-hua ZHAI,Yao-hui YANG,Wei SUN
n-octylphosphonic acid (OPA) was introduced as a novel collector for ilmenite flotation and its effectiveness was compared with the conventional chelating collector, benzohydroxamic acid (BHA). Micro-flotation tests demonstrated that OPA was a highly effective and selective collector for separating ilmenite from titanaugite over acidic conditions (optimal pH around 3), which was also supported by adsorption amount measurements. X-ray photoelectron spectroscopy (XPS) tests indicated that the chemisorption of OPA onto ilmenite surface was much stronger than that of BHA. Solution chemistry diagram analyses indicated that OPA could dissociate well at pH 3.0 and mostly exist in anion form. DFT calculations further confirmed that OPA was much easier to adsorb onto ilmenite surface with shorter bond length and lower adsorption energy in comparison with BHA. Therefore, OPA maintained good collecting ability and selectivity for ilmenite flotation in the strongly acidic pulp, providing valuable insights into new collector design and development.
A sustainable pathway to green hydrogen generation, the design and synthesis of targeted photocatalysts based on semiconductors or other organic/inorganic materials has emerged as a promising approach for efficient hydrogen production under light irradiation. In this paper, wollastonite-ZnIn 2 S 4 composite photocatalysts (ZIS-W) were successfully prepared by the chemical deposition method with wollastonite as the carrier. The hydrogen evolution reaction from water under simulated sunlight irradiation and the enhancement mechanism of ZIS-W were investigated. The results showed that ZIS-W exhibits favorable photocatalytic hydrogen evolution performance and stability, and the photocatalytic hydrogen evolution efficiency of ZIS-W was 4.94 mmol h −1 g −1 , which was 1.44 times higher than that of pure ZnIn 2 S 4 . The unique crystal structure of wollastonite provides favorable conditions for the growth of ZnIn 2 S 4 and effectively enhances the dispersion and stability of ZnIn 2 S 4 . The recombination of photogenerated electron-hole pairs was effectively suppressed while the specific surface area was increased. This study provided a facile synthesis method for preparing photocatalysts with highly efficient hydrogen generation.