In-suit fabrication of highly efficient CSH/glass fiber nanosheets adsorbent and development of secondary photocatalytic properties
摘要
Polluted water resulting from industrial activities is a significant source of heavy metal contamination. In this work, waste alkali-free glass fiber (E-GF) is converted into calcium silicate hydrate (CSH) nanosheets to form a CSH/E-GF composite by a one-step hydrothermal method, which is employed for the adsorption of Cu2+ in sewage. Based on the changes in elements and their contents, the formation mechanism of CSH was studied. The CSH/E-GF still maintains good tensile properties (962 MPa), which is beneficial for the recovery, even after in situ corrosion due to the excellent mechanical properties of E-GF. Benefiting from moderate surface area (62.3 m2/g), thin thickness (25 nm), in situ reaction capability, and excellent mechanical properties, the composite shows a notable adsorption capacity for Cu2+ (316.2 mg/g) along with exceptional stability. Furthermore, based on the pseudo-second-order model and fitting results, it was confirmed that the adsorption of Cu2+ ions by CSH is a chemical adsorption. Interestingly, after the adsorption of Cu ions, the semiconductor CuO can be formed by calcination, which can further degrade methylene blue (MB) through photocatalysis. The photocatalytic degradation rate of MB can reach 16.9% after 45 min. Additionally, the CSH/E-GF can be continuously recycled, and the degree of photocatalytic removal of MB remained 18.9% after five recycling runs. This paper provides new strategies for solving heavy metal and MB pollution in wastewater while simultaneously tackling waste glass fiber pollution.