In-situ synthesis of floating ZnIn2S4/cellulose foam for facile photocatalysis

Synergistically-mediated highly-efficient visible-light-driven hydrogen evolution activity using Ohmic/Schottky-type dual-junctions and sulfur vacancy

Enabling highly-efficient multiplex-optimization photocatalysts is critical to overcome the bottlenecks of hydrogen evolution reaction efficiency and photostability. Herein, novel CoS/Sv-ZnIn2S4/MoS2 composites are successfully synthesized through an in situ technique. Taking advantage of the synergistic effect of sulfur vacancy, Schottky-type MoS2/Sv-ZnIn2S4 junction and Ohmic-type CoS/Sv-ZnIn2S4 junction, the light absorption, electron/hole separation efficiency, charge transfer rate and hydrogen reduction reaction dynamic can be significantly enhanced. As a result, an impressive photocatalytic hydrogen evolution rate of 18.43 mmol g-1 h-1 is achieved under the visible-light irradiation. Furthermore, apparent quantum efficiencies of 72.14 % and 9.91 % are also achieved under 350 and 420 nm monochromatic light irradiation. This work presents an in situ perspective to design multiplex-optimization photocatalytic system for highly-efficient hydrogen production.

Visible light photocatalytic degradation of oxytetracycline hydrochloride using chitosan-loaded Z-scheme heterostructured material BiOCOOH/O-gC3N4

In this work, a Z-scheme heterostructured BiOCOOH/O-gC3N4 material was synthesized and immobilized on chitosan (CTS) to obtain the BiOCOOH/O-gC3N4/CTS photocatalytic material for photocatalytic degradation of oxytetracycline hydrochloride (CTC).Our findings indicate that the composite material BiOCOOH/O-gC3N4, as well as the BiOCOOH/O-gC3N4/CTS composite membrane, displayed a significantly higher efficiency in photocatalytic degradation of CTC compared to BiOCOOH alone, owing to the synergistic effect of adsorption and photocatalysis. Following four cycles of use, the composite material retained around 96 % of its initial photocatalytic degradation activity. The addition of CTS in the photocatalytic material resolved issues such as aggregation and difficult recovery commonly encountered with powder materials, thereby facilitating effective collision between the photocatalytic active sites and CTC. Experimental and theoretical calculations provided confirmation that the combination of BiOCOOH and O-gC3N4 effectively enhanced the light absorption capacity and photocatalytic performance. Furthermore, we investigated the influence of environmental factors such as pH value and anions on the photocatalytic degradation experiment, which offers valuable insights for the application of composite catalysts in wastewater treatment.

Construction of wood-PANI supercapacitor with high mass loading using "pore-making, active substance-filling, densification" strategy

Wood-conducting polymer materials have been widely used as supercapacitor electrode; however, it remains challenging to achieve a simple method to improve the homogeneity of the conductive material on wood and to reach high mass loading. Herein, a novel "pore-making, active substance-filling, densification (dissolution, in-situ polymerization of polyaniline (PANI), self-shrinking)" strategy is proposed for the preparation of wood electrodes with a high mass loading (41.4 wt%) and homogeneity. Ingeniously, ZnCl2 as a dissolving agent and pore-making agent to treat delignified wood can generate more pores on the wood, which is more conducive to the penetration of aniline small molecules, besides, the dissolved fine fibers can be entangled with more PANI, which can improve the loading and homogeneity of PANI. After drying treatment, there will be shrinkage again, playing a certain physical densification effect on the large lumen. The optical electrode was RWP2 showing high electrochemical performance (2328.9 mF/cm2, 1 mA/cm2), and stability (5000 cycles, 89.3 %). Moving forward, the RWP2//RWP2 SSC showed an excellent energy density of 164.24 μwh/cm2 at a power density of 250 μw/cm2. Remarkably, the simple and versatile strategy of designing wood-based materials with high mass loading provides new research ideas for realizing multifunctional applications.

Floating photocatalysts as promising materials for environmental detoxification and energy production: A review

The oxygenation process of the catalyst surface, the incident-light harvesting capability, and facile recycling of utilized photocatalysts play key role in the outstanding photocatalytic performances. The typical existing photocatalysts in powder form have many drawbacks, such as difficult separation from the treated water, insufficient surface oxygenation, poor active surface area, low incident-light harvesting ability, and secondary pollution of the environment. A great number of scientific works introduced novel and fresh ideas related to designing floating photocatalytic systems by immobilizing highly active photocatalysts onto a floatable substrate. Thanks to direct contact with the illuminated light and oxygen molecules in the interface of water/air, the photocatalytic performance is maximized through production of more reactive species, employed in the photocatalytic reactions. Furthermore, facile recovering of the utilized photocatalysts for next processes avoids secondary pollution as well as diminishes the process's price. This review highlights the performance of developed floating photocatalysts for diverse applications. Furthermore, different floating substrates and possible mechanisms in floating photocatalysts are briefly mentioned. In addition, several emerging self-floating photocatalytic systems are taken attention and discussed. Specially, coupling photo-thermal and photocatalytic effects seems to be a good strategy for introducing a new class of floating photocatalyst to utilize the free, abundant, and green sunlight energy for the aims of water desalination and purification. Despite of a large number of attempts about the floating photocatalysts, there are still plenty of rooms for more in-depth research to be carried out for attaining the required characteristics of the large scale utilizations of these materials.

Multifunctional Bagasse Foam with Improved Thermal Insulation and Flame Retardancy by a Borax-Induced Self-Assembly and Ambient Pressure Drying Technique

Cellulose foams are considered an effective alternative to plastic foam, because of their advantages of low density, high porosity, low thermal conductivity, and renewable nature. However, they still suffer from complex processing, poor mechanical properties, and flammability. As an agricultural waste, bagasse is rich in cellulose, which has attracted much attention. Inspired by the fact that borate ions can effectively enhance the strength of plant tissue by their cross-linking with polysaccharides, the present work designs and fabricates a series of multifunctional bagasse foams with robust strength and improved thermal insulation and flame retardancy via a unique borax-induced self-assembly and atmospheric pressure drying route using bagasse as a raw material, borate as a cross-linking agent, and chitosan as an additive. As a result, the optimized foam exhibits a high porosity (93.5%), a high hydrophobic water contact angle (150.4°), a low thermal conductivity (63.4 mW/(m·K) at 25 °C), and an outstanding flame retardancy. The present study provides a novel and inspiring idea for large-scale production of cellulose foams through an environmentally friendly and cost-effective approach.

Preparation of nanocellulose and its applications in wound dressing: A review

Nanocellulose, as a nanoscale polymer material, has garnered significant attention worldwide due to its numerous advantages including excellent biocompatibility, thermal stability, non-toxicity, large specific surface area, and good hydrophilicity. Various methods can be employed for the preparation of nanocellulose. Traditional approaches such as mechanical, chemical, and biological methods possess their own distinct characteristics and limitations. However, with the growing deterioration of our living environment, several green and environmentally friendly preparation techniques have emerged. These novel approaches adopt eco-friendly technologies or employ green reagents to achieve environmental sustainability. Simultaneously, there is a current research focus on optimizing traditional nanocellulose preparation methods while addressing their inherent drawbacks. The combination of mechanical and chemical methods compensates for the limitations associated with using either method alone. Nanocellulose is widely used in wound dressings owing to its exceptional properties, which can accelerate the wound healing process and reduce patient discomfort. In this paper, the principle, advantages and disadvantages of each preparation method of nanocellulose and the research findings in recent years are introduced Moreover, this review provides an overview of the utilization of nanocellulose in wound dressing applications. Finally, the prospective trends in its development alongside corresponding preparation techniques are discussed.