Search

The advancement in the development of nanofillers for thin-film nanocomposite (TFN) membranes, particularly those derived from eco-friendly sources, has gained increasing recognition. This is largely due to their potential to markedly improve both permeation and selectivity. However, the investigation of biochar (BC), a by-product of biomass pyrolysis, as a distinctive nanofiller remains limited. This study investigates the incorporation of porous iron/zinc (Fe/Zn) modified biochar (MBC) into a polyamide active layer for the purpose of fabricating TFN membranes on a polyethersulfone (PES) substrate via interfacial polymerisation (IP). Imaging confirmed the formation of metal nanoparticles dispersed uniformly throughout the porous BC substrate. Further crystallinity and surface analysis suggest strong interactions between metal and BC substrate, with a surface area of 117.99 m2/g and high nanofiller pore volume of 7.72 cm3/g. The effects of incorporating MBC into both the membrane substrate and polyamide (PA) layers on the physicochemical properties, permeation, and rejection of salts and dye were examined. Scanning Electron Microscopy (SEM) imaging has shown that the incorporation of MBC in both the substrate and PA layer results in the seamless formation of a finger-like structure spanning both layers. This incorporation also causes a minor increase in the surface roughness of the PA layer. Fourier transform Infra-Red (FT-IR) spectroscopy shows an enhancement in hydrophilic functional groups (–OH and –COOH) on the membrane surface, as evidenced by the reduced contact angle value of 55°. Permeation and rejection testing indicate that M5, where MBC was incorporated in both substrate and thin film structure, was the best performing membrane, with water permeance from the feeds of water, MO, MgSO4 and NaCl solutions of 46.55 ± 0.08, 44.49 ± 0.28, 37.43 ± 0.36, and 21.55 ± 0.03 Lm2h-1bar−1, respectively. Rejection of MO, MgSO4 and NaCl were recorded to be 99.53 ± 0.02

Researchers are actively pursuing the development of highly functional photocatalyst materials using environmentally friendly and sustainable resources. In this study, wheat straw biochar (BC), a by-product of biomass pyrolysis, was explored as a green, porous substrate and a carbon-based sensitizer to activate Fe-based photocatalysts under visible light. The research also delved into the impact of doping copper (Cu), chromium (Cr), and zinc (Zn) to enhance the photocatalytic activity of BC-Fe-based catalysts for the removal of methylene orange (MO) from water. Characterization results revealed a more than twofold increase in surface area and greater porosity, contributing to improved radical generation. BC demonstrated its dual functionality as a high surface area substrate and an electron sink, facilitating multistep electron movement and enhancing the photoactivity of the composite catalyst. Photodegradation experiments indicated that the combination of BC with Fe and Zn exhibited the highest performance, removing over 80% of MO within 120 min. Parametric studies highlighted the preference for an alkali pH, and the photocatalyst demonstrated efficient performance up to 30 ppm of dye. Radical scavenging experiments identified •OH and h+ as the most generated radicals. This study establishes that the green and sustainable BC holds promise as a material in the quest for more sustainable photocatalysts.

Ion–conducting ceramic membranes, such as mixed oxygen ionic and electronic conducting (MIEC) membranes and mixed proton–electron conducting (MPEC) membranes, have the potential for absolute selectivity for specific gases at high temperatures. By utilizing these membranes in membrane reactors, it is possible to combine reaction and separation processes into one unit, leading to a reduction in by–product formation and enabling the use of thermal effects to achieve efficient and sustainable chemical production. As a result, membrane reactors show great promise in the production of various chemicals and fuels. This paper provides an overview of recent developments in dense ceramic catalytic membrane reactors and their potential for chemical production. This review covers different types of membrane reactors and their principles, advantages, disadvantages, and key issues. The paper also discusses the configuration and design of catalytic membrane reactors. Finally, the paper offers insights into the challenges of scaling up membrane reactors from experimental stages to practical applications.

Fabricating dual-phase hollow-fiber membranes via a one-step thermal processing (OSTP) approach is challenging, because of complex sintering kinetics and the subsequent impacts on membrane morphology, phase stability, and permeation properties. In this study, we have demonstrated that Ce0.8Sm0.2O2-δ-SrCo0.9Nb0.1O3-δ (SDC-SCN) four-channel hollow fiber membrane can be manufactured via a single high-temperature sintering process, by using metal oxides and carbonates directly as membrane materials (sources of metal ions). It has been found that use of a low ramping rate reduces grain sizes, increases grain and forming cobalt oxide nanoparticles, a key step to promoting surface exchange process followed by enhancing oxygen permeation. While the grain boundary interface region can be limited to approximately 20–30 nm. At 1173 K oxygen permeation of the SDC-SCN four-channel hollow fiber membrane was measured at approximately 1.2 mL cm−2·min−1 using helium as the sweep gas. Meanwhile, the dual-phase membrane shows a good tolerance to carbon dioxide, with the oxygen permeation flux fully recovered after long-term exposure to carbon dioxide (more than 100 h). This will enable further application of the OSTP approach for preparing dual-phase multi-channel hollow fiber membranes for applications of oxyfuel combustion, catalytic membrane reactors and carbon dioxide capture.