Recycling difficult-to-degrade plastics, also known as “white pollution”, is currently being researched in the fields of materials and the environment, which is an extremely challenging topic. In this study, a pyrolysis-activation method combined with multiple activators was developed to prepare stable porous plastic chars (PPCs) from discarded plastic bottles for removing the typical antibiotic sulfamethoxazole (SMX). Micro/mesopores were formed in the PPCs, with the specific surface area reaching 961.20 m 2 /g. C, O, and N were the main elements in the PPCs, and their atomic ratios showed the hydrophobicity and aromaticity. Graphite-like structures and abundant surface functional groups were generated in the PPCs. Unlike conventional char materials, impurities, such as aluminum oxide, have high reflectivity, resulting in the appearance of many shining spots. PPCs display a high sorption capability for SMX, with the maximum sorption quantity determined reaching 487.52 mg/g. Multilayer sorption is dominated by physical processes, and pore filling, partitioning, hydrogen bonding, π-π stacking, and electrostatic interactions are the main sorption processes. Chemical-like sorption and mass transfer control the sorption rate. Furthermore, PPCs have stable performance and good recyclability and could be used for practical applications. This study provides a novel strategy and an example of the upcycling of discarded plastic as an excellent char material for environmental remediation.
Single component agent-based near-infrared phototheranostics has captivated researchers in cancer treatment over recent decades. However, the current single-component agents rarely alleviate the hypoxic microenvironment in tumor cells, which severely limits the development of photodynamic therapy. Here, we report a new phototheranostic agent, single-component black graphite carbon nitride nanoparticles (named CN-B NPs), synthesized through thermal copolymerization. Compared with unmodified graphitic carbon nitride (g-C3N4), the absorption of CN-B NPs in the near-infrared region was enhanced. Through in vitro and in vivo studies, we demonstrated that CN-B NPs can be used as a near-infrared phototheranostic agent in both normoxia and hypoxia, simultaneously allowing infrared thermal/photoacoustic imaging and photodynamic/photothermal co-therapy, thereby resulting in remarkable inhibition of tumor growth. This approach could provide a new method to achieve multimodal phototheranostics using a single-component material.
危险品化学品经营许可证（带存储）