RESUMO
The efficient and ecofriendly removal of pharmaceutical antibiotics and heavy metal Cr(VI) from water sources is a crucial challenge in current environmental management. Photocatalysis presents a viable environmentally friendly solution for eliminating organic contaminants and heavy-metal ions. In this study, a novel S-scheme CuInS2/ZnIn2S4 (CIS/ZIS) heterojunction was developed using a one-pot solvothermal method. The optimized CIS/ZIS heterojunction exhibited considerably improved photocatalytic activity for the removal of antibiotics and Cr(VI), achieving over 90% removal for both tetracycline hydrochloride (TC) (20 mg/L) and Cr(VI) (20 mg/L) under visible light irradiation. The study also delved into the effect of coexisting inorganic anions and assessed the cyclic stability of the composite photocatalysts. This enhancement mechanism can be delineated into three key elements. First, the incorporation of the narrow-gap semiconductor CuInS2 effectively augmented the photoabsorption capacity. Second, the inclusion of ZnIn2S4 caused an increase in surface active sites. Most importantly, the internal electric field at the interface between CuInS2 and ZnIn2S4 expedited the separation of photogenerated carriers. Furthermore, the results revealed that superoxide radical and photogenerated holes are the primary active substance responsible for TC removal, while photogenerated electrons play a central role in the photoreduction of Cr(VI). To gain insights into the transport pathways of photogenerated carriers, we conducted experiments with nitrotetrazolium blue chloride (NBT) and photodeposited gold. This study offers an innovative approach to enhancing the photocatalytic performance of ternary In-based materials by constructing S-scheme heterojunctions.
Assuntos
Antibacterianos , Cromo , Eletricidade , ElétronsRESUMO
The spills of crude oil and other organic chemicals are common around the world, resulting in severe damage to the environment and ecosystem. Therefore, developing low-cost and eco-friendly absorption material is in urgent need. In this study, we report a superhydrophobic and oleophilic porous material using biomass cuttlebone as the scaffold. A layer of polydopamine is grafted on the cuttlebone as the adhesion layer between the cuttlebone and the superhydrophobic coating. The in situ grown silica micro/nanoparticles on top of the adhesion layer provide the anchoring spots for grafting the fluorinated hydrocarbon and a rough topography for realizing superhydrophobicity. The static water contact angle of the superhydrophobic cuttlebone reaches 152°, and its oil contact angle is ~0°. The excellent oil-water separation efficiency of the prepared superhydrophobic cuttlebone is demonstrated using high-density oil/water mixtures and low-density oil/water mixtures.
RESUMO
In this study, nanocellulose/nanochitin membranes were prepared by suction filtrating 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofiber (TOCNF)/partially deacetylated α-chitin nanofiber (α-DECHN) mixed suspensions. The result shows that, with a 1:1 ratio of nanocellulose to nanochitin, the tensile strength of the obtained composite membrane reaches 115.7 MPa and its light transmittance is 77.6 %. Heptadecafluoro-1,1,2,2-tetrahydrodecyl dimethylchlorosilane (HFTD) modified nano SiO2 (F-SiO2), was utilized to construct rough micro/nanostructures on the surfaces of the composite membranes by screen printing, forming high-strength, transparent and superhydrophobic nanocellulose/nanochitin membranes. Atomic force microscope (AFM) images reveal that nanocellulose and nanochitin, with the width between 5 nm and 20 nm and the length between 400 nm and 1.1 µm, are crosslinked with each other. The superhydrophobic nanocellulose/nanochitin composite membranes functionalized with a 2.0 wt% F-SiO2 suspension has a few clusters on its surface. The contact angle of this membrane is 150.1°, and its light transmittance is 70.4 %.
