Synthesis of TiO2/H2Ti3O7 composite with nanoscale spiny hollow hierarchical structure for photocatalytic mineralization of VOCs

[Display omitted] •TiO2/H2Ti3O7 composite with nanoscale hollow and spiny structure was obtained.•Hollow structure enhanced light reflection in cavity.•Spiny structure enhanced light reflection among nanosheets.•Hollow and spiny structures are compatible for efficient light harvesting.•Mineralization efficiency of toluene and acetone was improved. Light absorption efficiency directly affects the photocatalytic degradation rate of volatile organic compounds (VOCs). Herein, we synthesized a TiO2 hierarchical structure with a nanoscale hollow cavity and ultrathin nanosheet-assembled shell to efficiently harvest light. The micromorphology, light absorption, and charge separation of the prepared catalysts were analyzed via transmission electron microscopy, scanning electron microscopy, UV–vis diffuse reflectance, and surface photovoltage measurements. The adsorption and photocatalytic degradation of toluene and acetone were conducted to evaluate the catalysts’ performance in VOC elimination. The prepared TiO2/H2Ti3O7 composite, FTHS, exhibited a spiny hollow morphology at the nanoscale, thereby considerably increasing its surface area and light absorption capacity compared with conventional TiO2 hollow spheres (THS). Moreover, the optimized structure of FTHS enhanced the charge separation and electron accumulation on the catalysts’ surface. Owing to these advantages, FTHS showed evidently higher adsorption amount, removal rate, and mineralization efficiency of toluene and acetone than THS.