•Multimorphologies nano-ZnOs were prepared.•A simple solvothermal method was used.•Diethylenetriamine controlling the morphology of ZnO.•Multimorphologies nano-ZnOs show excellent photocatalytic activity.A simple solvothermal method to successfully synthesize multimorphologies nano-ZnOs. The effect of diethylenetriamine on controlling the morphology of ZnO was studied by scanning electron microscopy (SEM). It is demonstrated that diethylenetriamine has significant influence on the two-dimension length of ZnO. Photocatalytic activities of as-prepared multimorphologies nano-ZnOs were also valuated using methyl orange as a model pollutant. The results show multimorphologies nano-ZnOs to have excellent photocatalytic activity.

The visible-light photocatalytic performance of the heterostructured g-C3N4/Ag/TiO2 microspheres was investigated. As an electron-conduction bridge, Ag nanoparticles were photodeposited as the interlayer between g-C3N4 and the surface of TiO2 microspheres to increase visible-light absorption via the surface plasmon resonance. The interface between Ag/TiO2 and g-C3N4 facilitates the direct migration of photoinduced electrons from g-C3N4 to Ag/TiO2, which is conductive to retarding the recombination of electron–holes. The g-C3N4 (4%)/Ag/TiO2 microsphere sample shows significant photocatalytic activity, higher than the sum of g-C3N4 (1.2 mg) and Ag/TiO2 samples, or the sum of TiO2 and Ag/g-C3N4 (1.8 mg) samples. It indicates that the heterostructured combination of g-C3N4, Ag and TiO2 microspheres provides synergistic photocatalytic activity through an efficient electron transfer process.Keywords: Ag; g-C3N4; heterostructured; photocatalysis; TiO2 microspheres; visible-light

•Macroporous ZnO/TiO2 films were synthesized using a template-free sol-gel method.•Surface wetting behavior was tested without UV irradiation.•The film with superhydrophilic and highly transparent.•Synergistic effects of porous structure and surface hydroxyl on superhydrophilicity.•Photocatalytic property was also studied under solar simulator irradiation.Superhydrophilicity of TiO2 thin film under natural conditions is of great importance for antifogging and self-cleaning applications of glass products. Transparent superhydrophilic porous ZnO/TiO2 composite films were prepared on glass substrates using a template-free sol–gel method. The results indicated that the porous ZnO (10%)/TiO2 composite film possesses superhydrophilicity with water contact angle less than 5° without UV irradiation. Surface chemical composition of the films was characterized by X-ray photoelectron spectroscopy (XPS). The morphologies of the porous films were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The porous morphology, crystal structure and surface chemical composition were significantly affected by ZnO addition. The natural superhydrophilic performance was attributed to the synergistic effect of the porous structure and surface hydroxyl groups. Photocatalytic activities of the ZnO/TiO2 composites were also evaluated using methyl orange (MO) as a model pollutant, with 78.1% of MO degraded by ZnO (10%)/TiO2, which was higher than 49.3% obtained from pure TiO2.

Porous TiO2/SiO2 (TS) composite thin films with superhydrophilic performance were successfully prepared by a sol–gel process under template-free conditions. The appearance of interconnected or isolated pores for the films was discussed in relation to the phase separation in the sol–gel process with the presence of acetylacetone (AcAc) and diethanolamine (DEA). The surface topography, crystal morphology and surface chemical composition of TS films, resulting in the changes of surface wetting property, were significantly affected by the molar content of SiO2. When the SiO2 content was 20%, the as-prepared TS composite thin films exhibited the optimum superhydrophilicity with a water contact angle (WCA) 2.5° without UV irradiation, and the spreading time was less than 1 s. The natural superhydrophilicity was attributed to the synergistic effect of SiO2 and phase-separation-induced porous structure.Highlights► Superhydrophilic porous TiO2/SiO2 films were prepared by a sol–gel process. ► Porous structure was induced by phase separation via controlling complexing agents. ► The addition of SiO2 affected the films surface topography and wetting performance. ► The film containing 20% SiO2 exhibited the optimum superhydrophilicity. ► The superhydrophilicity was ascribed to the addition of SiO2 and porous structure.