Zhishun Wei

The development of sustainable and efficient adsorbent materials for tetracycline hydrochloride (TCH) removal is of great importance for wastewater treatment. Structural characterizations (XRD and FTIR) confirmed successful lignin carbonization and the abundance of oxygen-containing functional groups, while N₂ physisorption revealed a phosphoric acid-induced hierarchical porous structure rich in mesopores to facilitate mass transfer. CL exhibited excellent tetracycline hydrochloride (TCH) adsorption, achieving a maximum capacity of 21.06 mg g⁻¹ within 2 h. The adsorption data closely followed the pseudo-second-order kinetic model, indicating a predominantly chemisorption process. While nanocellulose enabled the fabrication of flexible, self-supporting films with well-dispersed CL, excessive loading deteriorated film integrity. An optimized 30 wt% CL content achieved the ideal balance between structural stability and adsorption performance, demonstrating that these sustainable films hold great potential for aquatic antibiotic remediation.

Lignocellulosic films (LCFs) derived from biomass have attracted increasing attention owing to their abundant availability, recyclability, and biodegradability, making them promising candidates for replacing non-biodegradable plastics. Notably, the mechanical properties and wet stability of these materials play a crucial role in their practical applications. In this paper, we employ an eco-friendly and straightforward approach to synthesizing high-strength LCF by mixing nanocellulose with lignin. The incorporation of lignin enhances the mechanical strength for LCF, achieving a yield strength of 157.12 MPa at a lignin content of 15 wt% while simultaneously imparting excellent water absorption properties. Fourier transform infrared (FTIR) and contact angle measurements confirmed the structural integrity and hydrophilicity of the composite films. Excessive lignin content led to reduced mechanical performance, emphasizing the importance of optimizing the lignin-to-cellulose ratio. Therefore, this paper demonstrates the significant potential of LCF in developing environmentally friendly materials for applications in water treatment, packaging, flexible electronics, energy storage, and agriculture.

In this study, polyhedral self-assembled spherical titania (TS) photocatalyst was successfully synthesized via a one-step hydrothermal method from titanium chloride, sodium dodecyl sulfate and sulfuric acid. Titania modification with iron was carried out through the same procedure by the addition of different amounts of iron(III) chloride to the substrate mixture. Various methods were applied for sample characterization, e.g., XRD, SEM, TEM, XPS, UV-vis DRS, and photo-electrochemical measurements, such as EIS, CV, transient photocurrent, whereas photocatalytic activity was investigated for hydrogen evolution under UV/vis and oxidative decomposition of antibiotics under UV and/or vis, including also tests with scavengers. It has been found that iron was both incorporated in the titania structure (doping) and adsorbed on its surface. Although iron presence has hardly influenced the properties (slight changes in morphology, bandgap energy, and crystallite size), the photocatalytic activity has increased significantly. Therefore, it is proposed that iron might work as an electron sink, hindering the charge carriers’ recombination. Linear evolution of hydrogen, recycling experiments and characterization of samples after recycling have confirmed a good stability of iron-modified titania.

Photocatalysis has attracted more and more attention as a possible solution to environmental, water, and energy crises. Although some photocatalytic materials have already proven to perform well, there are still some problems that should be solved for the broad commercialization of photocatalysis-based technologies. Among them, cheap and easy recycling, as well as stability issues, should be addressed. Accordingly, the application of gels, either as a photocatalytic material or as its support, might be a good solution. In this review, various propositions of gel-based photocatalysts have been presented and discussed. Moreover, an easy nanoarchitecture design of gel-based structures enables fundamental studies, e.g., on mechanism clarifications. It might be concluded that gels with their unique properties, i.e., low density, high specific surface area, great porosity, and low-cost preparation, are highly prospective for solar-energy-based reactions, water treatment, photodynamic cancer therapies, and fundamental research.

Photocatalysis is considered as an environmentally friendly method for both solar energy conversion and environmental purification of water, wastewater, air, and surfaces. Among various photocatalytic materials, titania is still the most widely investigated and applied, but more efforts must be carried out considering the synthesis of highly efficient photocatalysts for multifarious applications. It is thought that nanoengineering design of titania morphology might be the best solution. Accordingly, here, titania mesocrystals, assembled from crystallographically oriented nanocrystals, have been synthesized by an easy, cheap, and “green” solvothermal method (without the use of surfactants and templates), followed by simple annealing. The obtained materials have been characterized by various methods, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and diffuse reflectance spectroscopy (DRS). It has been found that the as-obtained photocatalysts exhibit a unique nanorod-like subunit structure with excellent crystalline and surface properties. However, pristine titania is hardly active for a hydrogen evolution reaction, and thus additional modification has been performed by platinum photodeposition (and silver as a reference). Indeed, the modification with only 2 wt% of noble metals results in a significant enhancement in activity, i.e., ca. 75 and 550 times by silver- and platinum-modified samples, respectively, reaching the corresponding reaction rates of 37 μmol h⁻¹ and 276 μmol h⁻¹. Additionally, titania mesocrystals exhibit high oxidation power under simulated solar light irradiation for the degradation of antibiotics within the tetracycline group (tetracycline (TC), ciprofloxacin (CIP), norfloxacin (NOR) and oxytetracycline hydrochloride (OTC)). It has been found that both experimental results and the density functional theory (DFT) calculations confirm the high ability of titania mesocrystals for oxidative decomposition of tetracycline antibiotics.

Anatase TiO₂ hierarchically structured microspheres with co-exposed {001}/{101} facets were prepared by a facile one-pot hydrothermal method. The influences of reaction temperature on the morphology and crystallization of microspheres were investigated systematically. The obtained microspheres possessed better morphology and crystallization when the reaction temperature was 160 °C. Different noble metals (Au, Ag, Cu, Pt, Pd) were used for the microspheres modification, and the experimental results exhibited that the photocatalytic activities of the noble metal modified microspheres were enhanced obviously, especially for the Pt-modified sample (TPt), which showed the highest photocatalytic activity in degradation of tetracycline hydrochloride (the TPt sample showed the largest improvement, i.e., the activity reached 1.47 times higher than that of the bare sample) and hydrogen production (the largest improvement was also observed for the TPt sample, i.e., the activity was more than 30 times as the bare sample, reaching more than 300 μmol·g⁻¹·h⁻¹). Finally, a photocatalytic reaction mechanism involving the synergy of co-exposed {001}/{101} crystal facets with noble metals was proposed according to the as-obtained experimental results.

Single crystalline anatase TiO₂ microspheres with co-exposed {001}/{101} facets were prepared by a facile one-pot hydrothermal method using NaF as a morphology controlling agent. The influences of the NaF amount on the morphology and also on the photocatalytic activity were investigated systematically. The obtained microspheres possessed better morphology when the concentration of NaF was chosen at 0.1 mol/L, and the experimental results indicated that the crystal structure and morphology played important roles on the photocatalytic activity, based on the experimental results it was found that the photocatalytic degradation efficiency of TiO₂ microspheres on Tetracycline hydrochloride could reach 76.4% in 2 h. Finally, a growth mechanism was proposed by investigating the growth process, i.e., a synergistic effect of F ions modified Ostwald ripening and oriented attachment.