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Solar-driven interfacial evaporation is a sustainable and green desalination method with great prospects for development in today's severe water shortage problem. In this paper, a novel composite aerogel was prepared by hydrothermal method with sodium alginate (SA) and Cu2+ in the preparation process using reduced graphene oxide as photothermal material and cellulose nanofibers as substrate. The good hydrophilicity of nanocellulose makes the composite aerogel have strong capillary action and continuous water transport. The gel formed by ion exchange between SA and Cu2+ greatly improves dry and wet mechanical strength of the composite aerogel and ensures the stability of the evaporator for multiple recycling. Copper is doped by reduction of copper ion complexes and reduced graphene oxide have a synergistic effect to increase the photothermal response rate of the composite aerogel of 1.446 kg m−2 h−1 with evaporation efficiency of 84.87% under one standard solar irradiation. In addition, the purification of heavy metal ions, dye wastewater as well as acid and alkali solutions also has excellent results. It is expected that this study will provide some new ideas for the fields of seawater desalination and wastewater treatment. [ABSTRACT FROM AUTHOR]

Active catalysts that were prepared by dispersing copper (Cu) nanoparticles on potassium hydroxide (KOH)-activated carbon aerogels (ACAs) were investigated in the synthesis of dimethyl carbonate (DMC) by vapor-phase oxidative carbonylation of methanol. The effect of mesopores and surface oxygen-containing groups (OCGs) including C = O, COOH and OH of the ACAs on the dispersion of active species and catalytic properties was determined. An increase in molar ratio of resorcinol to anhydrous sodium carbonate (R/C) lead to the creation of mesopores within the original carbon aerogels (CAs), which benefits to molecules mass transport. The amount of surface OCGs increased positively with KOH/CAs mass ratio, which affected the valence distribution of Cu species, improved the Cu dispersion and enhanced the catalytic activity. For an optimum R/C of 500 and a KOH/CAs mass ratio of 4, the Cu/ACAs catalyst maintains a prominent DMC space time yield of 338.7 mg/(g h) and a methanol conversion of 2.5%. Density functional theory calculations indicate that of the different surface OCGs of the carbon support, enrichment in C = O group enhances the interaction between the metal and the ACAs support significantly and contributes to the formation of the smallest Cu nanoparticles and the highest catalytic activity. [ABSTRACT FROM AUTHOR]