Biomimetic layer-by-layer deposition assisted synthesis of Cu, N co-doped TiO2 nanosheets with enhanced visible light photocatalytic performance

Waste Biomass-Mediated Synthesis of TiO2/P, K-Containing Grapefruit Peel Biochar Composites with Enhanced Photocatalytic Activity

In this study, TiO2/P, K-containing grapefruit peel biochar (TiO2/P, K-PC) composites were synthesized in situ biomimetically using grapefruit peel as the bio-template and carbon source and tetrabutyl titanate as the titanium source. This was achieved using the two-step rotary impregnation-calcination method. Adjusting the calcination temperature of the sample in an air atmosphere could regulate the mass ratio of TiO2 to carbon. The prepared samples were subjected to an analysis of their compositions, structures, morphologies, and properties. It demonstrated that the prepared samples were complexes of anatase TiO2 and P, K-containing carbon, with the presence of graphitic carbon. They possessed a unique morphological structure with abundant pores and a large surface area. The grapefruit peel powder played a crucial role in the induction and assembly of TiO2/P, K-PC composites. The sample PCT-400-550 had the best photocatalytic activity, with the degradation rate of RhB, MO, and MB dye solutions reaching more than 99% within 30 min, with satisfactory cyclic stability. The outstanding photocatalytic activity can be credited to its unique morphology and the efficient collaboration between TiO2 and P, K-containing biochar.

Activation of 2D titanate nanosheet photocatalysts by nitrogen doping and solution plasma processing

Novel two-dimensional (2D) oxides are of great interest for photocatalysis because of their superlative physical features, namely, large surface areas, short charge diffusion pathways, high crystallinity and easy surface modification. However, most 2D oxides suffer from weak visible light absorption and severe photogenerated carrier recombination. Nitrogen doping can successfully narrow the bandgap of 2D oxides but can hardly improve the charge separation. In this work, we pre-dope nitrogen into 2D titanate nanosheets (HTiO), followed by surface processing with solution plasma. By dual modification of nitrogen doping and solution plasma processing (SPP), the modified 2D titanate nanosheets (N-HTiO-SPP) display broad absorption extending to the visible light region and the healing of oxygen vacancies brought about by nitrogen doping. Compared with HTiO and nitrogen doped titanate (N-HTiO), a higher removal rate and mineralization rate towards the photocatalytic degradation of acetaldehyde were achieved over N-HTiO-SPP under solar light. This work provides a powerful way to activate 2D wide bandgap semiconductors for enhanced photocatalytic activity.

Superior visible light antimicrobial performance of facet engineered cobalt doped TiO2 mesocrystals in pathogenic bacterium and fungi

Pristine and Co-doped TiO2 mesocrystals have been synthesized via a simple sol-gel method and their antimicrobial activity has been investigated. The antimicrobial performance was evaluated in terms of zone of inhibition, minimum inhibitory concentration (MIC), antibiofilm activity, and effect of UV illumination in liquid media. The Co-doped TiO2 mesocrystals showed very promising MIC of 0.390 μg/mL and 0.781 μg/mL for P. mirabilis and P. mirabilis, respectively. Additionally, the material showed an MIC of 12.5 μg/mL against C. albicans, suggesting its use as antifungal agent. Upon the addition of 10.0 µg/mL of Co-doped TiO2 mesocrystals, the biofilm inhibition% reaches 84.43% for P. aeruginosa, 78.58% for P. mirabilis, and 77.81% for S. typhi, which can be ascribed to the created active oxygen species that decompose the tested microbial cells upon illumination. Thus the fabricated Co-doped TiO2 mesocrystals exhibit sufficient antimicrobial features under visible light, qualifying them for use as antimicrobial agents against pathogenic bacteria and fungi and subsequently inhibit their hazardous effects.

In situ synthesis of novel Cu2CO3(OH)2 decorated 2D TiO2 nanosheets with efficient photocatalytic H2 evolution activity

Semiconductor-based photocatalytic hydrogen evolution from water with earth-abundant and low cost co-catalysts has attracted much attention.

Nanostructured BN–TiO2 composite with ultra-high photocatalytic activity

Boron nitride and titanium oxide composite (BN–TiO₂) photocatalyst endowed with high specific surface area and large pore size was synthesized by ice bath method.

C–N–S tridoping into TiO2matrix for photocatalytic applications: observations, speculations and contradictions in the codoping process

C–N–S-tridoped TiO₂: behind and beyond the codoping process.

Black N/H-TiO2 Nanoplates with a Flower-Like Hierarchical Architecture for Photocatalytic Hydrogen Evolution

A facile two-step strategy was used to prepare black of hydrogenated/nitrogen-doped TiO₂ nanoplates (NHTA) with a flower-like hierarchical architecture. In situ nitriding and self-assembly was realized by hydrothermal synthesis using tripolycyanamide as a N source and as a structure-directing agent. After thorough characterization, it was found that the hydrogenation treatment did not damage the flower-like architecture but distorted the anatase crystal structure and significantly changed the band structure of NHTA owing to the increased concentration of oxygen vacancies, hydroxyl groups, and Ti³⁺ cations. Under AM 1.5 illumination, the photocatalytic H₂ evolution rate on the black NHTA was approximately 1500 μmol g^-1  h^-1 , which was much better than the N-doped TiO₂ nanoplates (≈690 μmol g^-1  h^-1 ). This improvement in the hydrogen evolution rate was attributed to a reduced bandgap, enhanced separation of the photogenerated charge carriers, and an increase in the surface-active sites.

Hydrothermal synthesis of Co–ZnO nanowire array and its application as piezo-driven self-powered humidity sensor with high sensitivity and repeatability

Self-powered humidity sensor with high sensitivity and repeatability has been fabricated from Co-doped ZnO NW arrays. Such a high performance can be attributed to the piezo-surface coupling effect and more active sites introduced by the Co dopants.

A novel photocatalyst CeF3: facile fabrication and photocatalytic performance

The synthesized CeF₃ nanoparticles can effectively decompose organic contaminants in aqueous solution and show high stability.