Spatial Heterojunction in Nanostructured TiO2 and Its Cascade Effect for Efficient Photocatalysis

A highly efficient photoenergy conversion is strongly dependent on the cumulative cascade efficiency of the photogenerated carriers. Spatial heterojunctions are critical to directed charge transfer and, thus, attractive but still a challenge. Here, a spatially ternary titanium-defected TiO₂@carbon quantum dots@reduced graphene oxide (denoted as V_Ti@CQDs@rGO) in one system is shown to demonstrate a cascade effect of charges and significant performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as H₂ production from water splitting and CO₂ reduction. A key aspect in the construction is the technologically irrational junction of Ti-vacancies and nanocarbons for the spatially inside-out heterojunction. The new "spatial heterojunctions" concept, characteristics, mechanism, and extension are proposed at an atomic-/nanoscale to clarify the generation of rational heterojunctions as well as the cascade electron transfer.

One-step synthesis of core shell cellulose-silica/n-octadecane microcapsules and their application in waterborne self-healing multiple protective fabric coatings

Exploiting water-based fabric coatings outfitted with multiple protections (e.g., waterproofness, ultraviolet (UV) resistance and thermal insulation) are urgently demanded. Nevertheless, achieving the multifunction and durability poses the major challenge. In the present study, novel multifunctional cellulose/silica hybrid microcapsules were developed by one-step emulsion-solvent diffusion; these microcapsules were well dispersed into waterborne silicone resins to form waterborne multiple protective fabric coatings. Since the encapsulated phase change materials were in the core of capsules, and the hydrophobic coupling reagent and UV absorber were grafted onto the silicas in the shell of capsules, these fabric coatings exhibited high superhydrophobicity, UV protection and thermal insulation. Moreover, because hydrophobic coupling reagent and UV absorber in the shell-cellulose of capsules exhibited easy mobility, the fabric coatings displayed self-repairability of superhydrophobicity and UV protection even after being damaged chemically or mechanically. The fabric coating presented in this study could have a range of applications, covering special protective fabric, high-altitude garments as well as self-cleaning materials.

The synthesis of bayberry-like mesoporous TiO2 microspheres by a kinetics-controlled method and their hydrophilic films

Bayberry-like mesoporous TiO₂ hydrophilic films with high surface roughness and high density of surface hydroxyl groups.