Construction of an integrated multi-layer textile for solar-driven steam generation.

Solar steam generation has widespread application in wastewater treatment, seawater desalination, liquid-liquid separation, and other fields, providing potential opportunities for producing fresh water. Up until now, most researchers in this field focused on enhancing the evaporation rate of the solar steam generation device. However, problems in terms of its portability and flexibility still exist when it comes to real application scenarios. Herein, we propose a novel, to the best of our knowledge, integrated multi-layer textile composed of reduced graphene oxide/cotton (RGO/cotton) fabric, cotton yarn, and polypropylene (PP) fabric for solar-driven steam generation. The evaporation rate obtained by the integrated multi-layer textile as prepared is ${0.83}\;{{\rm kg\cdot m}^{- 2}}\cdot{{\rm h}^{- 1}}$ under one sun solar radiation, which is 3.16 times higher than that of blank experiment and is superior to many previously reported works. Its remarkable evaporation performance is mainly attributed to the inherent multi-layer structures, where porous RGO/cotton fabric exhibits ultra-water vapor permeability, hydrophilic cotton yarn supplies water continuously, and low-density hydrophobic PP fabric hinders heat sustainably. Based on the results of application performance evaluation, the integrated multi-layer textile with scalable manufacturability, portability, durability, and flexibility is expected to boost the development of solar-driven steam generation.

Smart surfaces with reversibly switchable wettability: Concepts, synthesis and applications.

As a growing hot research topic, manufacturing smart switchable surfaces has attracted much attention in the past a few years. The state-of-the-art study on reversibly switchable wettability of smart surfaces has been presented in this systematic review. External stimuli are brought about to render the alteration in chemical conformation and surface morphology to drive the wettability switch. Here, starting from the fundamental theories related to the surfaces wetting principles, highlights on different triggers for switchable wettability, such as pH, light, ions, temperature, electric field, gas, mechanical force, and multi-stimuli are discussed. Different applications that have various wettability requirement are targeted, including oil-water separation, droplets manipulation, patterning, liquid transport, and so on. This review aims to provide a deep insight into responsive interfacial science and offer guidance for smart surface engineering. It ends with a summary of current challenges, future opportunities, and potential solutions on smart switch of wettability on superwetting surfaces.

Hydrothermal synthesis of cotton-based BiVO4/Ag composite for photocatalytic degradation of C.I. Reactive Black 5.

Photocatalytic materials with high efficiency and convenient recyclability have attracted great interest for the treatment of printing and dyeing wastewater. In this paper, a narrow band gap BiVO4 photocatalyst was loaded onto Ag modified cotton fabric by a hydrothermal method. The prepared composite materials were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible light absorption spectroscopy (UV-vis). The composite materials as prepared show superb photocatalytic activity and reusable performance for the degradation of C.I. Reactive Black 5 (RB5). The degradation rate can reach 99% within 90 min under 1 kW xenon lamp irradiation, and over 90% of the photocatalytic performance is preserved even after five recycles. Furthermore, the photocatalytic mechanism was proposed by spectral analysis and free radical trapping experiments.

Preparation and photocatalytic activity characterization of activated carbon fiber-BiVO4 composites.

Herein, we describe the hydrothermal immobilization of BiVO4 on activated carbon fibers (ACFs) and characterize the obtained composite by several instrumental techniques, using Reactive Black KN-B (RB5) as a model pollutant for photocatalytic performance evaluation and establishing the experimental conditions yielding maximal photocatalytic activity. The photocatalytic degradation of RB5 is well fitted by a first-order kinetic model, and the good cycling stability and durability of BiVO4@ACFs highlight the potential applicability of the proposed composite. The enhanced photocatalytic activity of BiVO4@ACFs compared to those of BiVO4 and ACFs individually was mechanistically rationalized, and the suggested mechanism was verified by ultraviolet-visible spectroscopy, attenuated total reflectance Fourier-transform infrared spectroscopy, and RB5 degradation experiments. Thus, this work contributes to the development of BiVO4@ACF composites as effective photocatalysts for environmental remediation applications.

Laccase immobilization and surface modification of activated carbon fibers by bio-inspired poly-dopamine.

In this study, we developed a new synthesis method for modifying activated carbon fibers (ACFs) by dopamine with oxidation-based self-polymerization (DA-ACFs). In addition, laccase was immobilized on the surface of unmodified ACFs (L-ACFs) and DA-ACFs (LDA-ACFs) via cross-linking after being incubated for 12 h at 5 °C. The surface composition and microstructure of the samples were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier-transform infrared reflection and thermo-gravimetric analysis. The optimized laccase concentration for preparing the samples was 2.0 g L-1. The results demonstrated that the successful poly-dopamine modification increased the catalytic abilities of the ACFs in terms of biocompatibility and hydrophilicity. Compared with free laccase, the immobilized laccase exhibited significantly higher relative activity over a pH range of 3.5-6.5 and a temperature range of 30-60 °C; the thermo-stability increased, and 50% relative activity of the LDA-ACFs remained after 5 h at 55 °C. After six cycles of reuse, the relative activity of LDA-ACFs remained ≥60%, compared to 40% activity remaining for L-ACFs, and long-term storage stability was demonstrated. Moreover, the kinetic parameters (K m) of the two immobilized laccases were both higher than that of free laccase, whereas the maximum velocities (V max) were lower. These results indicate that the DA-ACFs are economical, simple, and efficient carries for enzyme immobilization, and can be suitable for further biotechnology and environmental applications.