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TiO2‐based composite photocatalysts are currently being explored to address concerns intrinsic to TiO2, specifically high charge carrier recombination and UV light activation. Among various materials utilized for composite formation, carbon nanomaterials stand out due to their high electron conductivity, charge storage, photosensitization, and surface properties. However, high carbon content in composites has been shown to reduce performance with potential toxicity concerns. To harness the diverse properties of carbon nanomaterials in a single composite while optimizing the carbon content below 1% by weight, multi‐walled carbon nanotubes (MWCNT)/TiO2 sensitized by carbon nanodots (CND) are synthesized. The heterojunction formed between MWCNTs and TiO2 in the binary composite reduced the charge carrier recombination rate compared to TiO2. The addition of CNDs to MWCNT/TiO2 induced visible light absorbance of the resulting ternary composite, due to the forbidden electron transitions undergone in CND aggregates. CND/MWCNT/TiO2 exhibited a fivefold and 1.6‐fold increase in photocatalytic degradation of acid orange 7 and tetracycline under visible light compared to TiO2. This enhancement is attributed to the photosensitizing property of CNDs working in synergy with the charge storage ability of MWCNTs. A plausible charge transfer pathway for the activity of CND/MWCNT/TiO2 is proposed. [ABSTRACT FROM AUTHOR]

Joining thermoplastic polymers (TPMs) and metals to form lightweight hybrid structures is of growing industrial and commercial importance. The performance of such materials relies on the bonding strength and endurance of the formed TPM–metal interfaces. The available joining technologies and the mechanisms that govern interfacial adhesion are reviewed in this contribution, highlighting thermal bonding as a commercially attractive joining method. By focusing on molecular interactions to optimize interfacial adhesion, the use of dopamine as a building block to form polydopamine (PDA) based adhesive interlayers in such interfaces is discussed. This work also highlights the potential of PDA to be applied as a load‐bearing adhesive—a notion considered to date unfeasible. [ABSTRACT FROM AUTHOR]

Enhanced photocatalytic activity of rutile-based TiO2 materials under general lighting is practically desired. O2 plasma-assisted annealing (PAA) effects on Pt-doped rutile TiO2 nanoparticles were clarified along with its visible-light-driven photocatalytic activity enhancement. The PAA-treated samples were mainly analyzed using optical spectroscopy and x-ray photoelectron spectroscopy (XPS). The photocatalytic activity was assessed by decomposing methylene blue dye and inactivating Bacillus subtilis under general lighting. The PAA treatment changed the O 1s, Ti 2p, and Pt 4f spectra of XPS from those of the pristine sample. This change indicated that the PAA treatment introduced more oxygen deficiency or oxygen vacancies and more oxygen groups adsorbed on the surface. The introduced oxygen vacancies and adsorbed oxygen groups would change the band structure, which primarily narrowed the bandgap energy or broadened the valence band edge, increased the number of electron-trapping sites from the shallow to midgap levels, and enhanced the upward band-bending at the surface. The PAA-induced change in the band structure enhanced the decomposition and bacterial inactivation because it facilitated the separation and concentration of photoexcited carriers. The findings provide a new perspective on enhancing the photocatalytic activities of rutile-based TiO2 nanoparticles under general lighting. [ABSTRACT FROM AUTHOR]

Surface modification of heterogeneous photocatalysts with single‐atom catalysts (SACs) is an attractive approach for achieving enhanced photocatalytic performance. However, there is limited knowledge of the mechanism of photocatalytic enhancement in SAC‐modified photocatalysts, which makes the rational design of high‐performance SAC‐based photocatalysts challenging. Herein, a series of photocatalysts for the aerobic degradation of pollutants based on anatase TiO2 modified with various low‐cost, non‐noble SACs (vanadate, Cu, and Fe ions) is reported. The most active SAC‐modified photocatalysts outperform TiO2 modified with the corresponding metal oxide nanoparticles and state‐of‐the‐art benchmark photocatalysts such as platinized TiO2 and commercial P25 powders. A combination of in situ electron paramagnetic resonance spectroscopy and theoretical calculations reveal that the best‐performing photocatalysts modified with Cu(II) and vanadate SACs exhibit significant differences in the mechanism of activity enhancement, particularly with respect to the rate of oxygen reduction. The superior performance of vanadate SAC‐modified TiO2 is found to be related to the shallow character of the SAC‐induced intragap states, which allows for both the effective extraction of photogenerated electrons and fast catalytic turnover in the reduction of dioxygen, which translates directly into diminished recombination. These results provide essential guidelines for developing efficient SAC‐based photocatalysts. [ABSTRACT FROM AUTHOR]

The basement membrane (BM) is a biointeractive ultrathin network with distinct composition and organization of its epithelial and stromal sides, which render BMs with asymmetric biofunctions and mechanical properties. There are difficulties in the recapitulation of the highly hierarchical structure and function of BM. Here, the interfacial assembly method for the generation of BM mimics is applied. Dopamine is the starting material for the polymerization and assembly of polydopamine (PDA) into asymmetric materials. Compared to the PDA coating formed at the solid/liquid interface (≈20 nm), the PDA film formed at the air/liquid interface displays a thickness of ≈100 nm. Moreover, it possesses an asymmetric surface topography and an apparent Young's modulus of ≈1.0 MPa, which is structurally and mechanically similar to natural BMs. Of interest, the airside and the waterside of the PDA film exhibit differences in their adhesion affinity to the human skin keratinocytes. With stronger active mechanical processes between living cells and the waterside of PDA film, epithelial folding could be mimicked. Together, the PDA film is able to recapitulate the structural and mechanical complexity of natural BMs, indicating the prospective future of using PDA films for in vitro modeling cell‐BM interaction and tissue formation. [ABSTRACT FROM AUTHOR]

In this paper we report the sensitivity of porous silicon photoluminescence (PL) to diluted mixtures of methane and carbon monoxide in synthetic air. We also investigate the separate effect of synthetic air, purified nitrogen and relative humidity on both photoluminescence and conductance (G). Porous silicon samples have been prepared from n-type silicon substrates. We find that PL intensity and G decrease in synthetic air with respect to their values in N2. Presence of carbon monoxide reduces the PL intensity while methane provokes the opposite behaviour. The dependence of the PL spectra on methane and carbon monoxide concentrations has been investigated. The observed effects can be related to gas induced modifications in porous surface and suggest that porous silicon can be employed in gas sensor technology. [ABSTRACT FROM AUTHOR]