The discharge of organic pollutants by the textile and dyeing industries presents an escalating threat to aquatic environments, necessitating the development of effective remediation strategies. This study introduces the utilization of graphite-like structured activated carbon (AC), derived from highland barley straw-a biomass unique to the Plateau regions of China, including Tibet, Qinghai, and Gansu-as a support material for the TiO₂ catalyst. TiO₂/AC composites with different TiO₂ loadings were synthesized by ultrasonic impregnation. The TiO₂/AC composites were found to be polycrystalline materials composed of anatase and rutile phases. The TiO₂ nanoparticles are well-dispersed over the surface of the AC. The photocatalytic activity of these composites was evaluated through their capacity to degrade a methylene blue (MB) solution upon irradiation. It was observed that the inclusion of TiO₂ increases the number of adsorption sites and active sites for methylene blue, with the photocatalytic activity being notably higher at a 3-wt% TiO₂ loading, achieving a remarkable 99.6 % degradation efficiency for 100 mg/L MB within 100 min. The experimental kinetic data for the photocatalytic process follow the pseudo-first-order kinetic model. Furthermore, TiO₂/AC retains high photocatalytic activity after five reaction cycles. This research provides valuable insights into the application of biomass-derived materials for the purification of water, offering a sustainable solution to both pollution and agricultural waste challenges in Plateau areas of China.

We reported anchoring mesoporous silica onto the microporous metal–organic frameworks (MOF) (UiO-66-NH₂) to obtain a hierarchical porous framework (UiO-66-NH₂@SiO₂). This strategy maintains the high specific surface area (SA) of the MOF and addresses the mass transfer issue frequently encountered in microporous materials, providing more possibilities for subsequent modified structural frameworks. The structural characteristics of UiO-66-NH₂@SiO₂ were evaluated by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, surface analysis and X-ray photoelectron spectroscopy. In this work, the specific SA of the composite material was 196.667 m²/g, which decreased due to the occupation of some pores by anchored silica. Adsorption experiments showed that the composite material had a better adsorption effect (Congo red, 393.83 mg/g; bromophenol blue, 446.46 mg/g) than UiO-66-NH₂, with electrostatic interaction and hydrogen bonding being the main driving forces. Therefore, this is a material that has a positive impact on dye adsorption. The strategy proposed in this work has potential applications not only in the construction of new materials but also in the exploration of dye adsorbents.