The BaTiO₃?TiO₂ composites were prepared by using hydrate barium hydroxide (Ba(OH)₂·8H₂O) and titanium dioxide (TiO₂) as raw materials with soft chemical hydrothermal method at 120 ℃ and different Ba/Ti molar ratios.The structure of the prepared composites with different Ba/Ti molar ratios was analyzed by X?ray diffraction (XRD),scanning electron microscopy (SEM),and UV?visible absorption spectroscopy (UV?Vis),the degradation effect of the complex on the simulated degradation pollutant,rhodamine B (RhB) was investigated.The results indicate that the BaTiO₃?TiO₂ composites obtained at a Ba/Ti molar ratio of 0.50 have an excellent catalytic effect for the degradation of rhodamine B (RhB) during the simulation of dye wastewater degradation.Meanwhile,more active sites formed at the Ba/Ti molar ratio of 0.50, which facilitated the photocatalytic reaction.

Titanium dioxide (TiO₂) is a traditional photocatalyst material.However, due to its wide band gap (3.2 eV) and the easy recombination of photogenerated carriers,it is necessary to enhance the effective absorption of sunlight,promote the separation of photogenerated carriers,and inhibit their recombination by doping noble metals,transition metals,anions and constructing heterojunctions.TiO₂/CdS heterojunctions were prepared in two steps.Firstly,TiO₂ nanotube arrays were prepared by multiple voltage anodization.Then,with TiO₂ nanotubes as the base,CdS quantum dots were uniformly deposited inside and outside the nanotubes through chemical bath deposition.The composition,morphology,and optical properties of TiO₂/CdS heterojunctions were characterized by X?ray diffraction,scanning electron microscopy (SEM),transmission electron microscopy (TEM),X?ray photoelectron spectroscopy (XPS),and UV?visible spectroscopy (UV?VIS).The prepared TiO₂/CdS heterojunctions effectively inhibited the recombination of photogenerated carriers,promoted the transfer of excited electrons,and improved the hydrogen production efficiency by photocatalysis.The hydrogen production efficiency of sample TiO₂(1.0)?CdS(1.0) reached 1.30 mmol/（g ? h）,which was 1.67 times that of CdS quantum dots.Finally,according to the experimental analysis,the transfer mechanism of photogenerated electrons on TiO₂/CdS during photocatalytic water splitting for hydrogen was proposed.

Formation damage control of Hutubi underground gas storage (UGS) presents a serious challenge due to low formation pressure coefficient and reservoir deep invasion of wellbore working fluid under large pressure difference during drilling and completion. Mineral composition analysis, expansion capacity, wettability and permeability reduction after spontaneous imbibition measurement of reservoir rocks were conducted to reveal formation damage mechanism of Hutubi UGS. That is the clay minerals hydrated swell and dispersion of water?sensitive formation and water?blocking effect of tight sand reservoir. Drilling fluid technical countermeasure of improving inhibition, weakening liquid wettability and enhancing temporary plugging was put forward. Amine inhibitor and surfactant ABSN were selected to optimize the current used drilling fluid. Temporary plugging particle size fraction distribution was determined based on the “optimal filling” bridging plugging theory. Laboratory and field evaluation show that the optimized drilling fluid is suitable for perforation and screen pipe completion with a permeability recovery more than 90% and effective inhibition of clay swell. The results provide reference for improving formation damage control effect of depleted gas reservoir drilling and completion.