A pH-responsive cascade nanoplatform with circulating oxygen supply for collaborative breast cancer treatment.

A pH-responsive cascade nanoplatform based on ZIF-8 disintegrates in the weakly acidic tumor microenvironment to release MnO2, CaO2 and Ce6. The drugs can cyclically generate O2 for sonodynamic therapy, consume glutathione to tune the redox hemostasis, and produce cytotoxic ˙OH to kill tumor cells via chemical dynamics therapy.

3D macroporous CUPC/g-C3N4 heterostructured composites for highly efficient multifunctional solar evaporation.

Solar-driven interfacial evaporation is a promising technology for water recycling and purification. A sustainable solar evaporation material should have not only high photothermal conversion efficiency, but also an ecofriendly fabrication process as well as pollutant degradation and sterilization properties. We present in this work a solar evaporator based on graphitic carbon nitride (g-C3N4) and copper phthalocyanine (CUPC) composites with typical type-I heterojunctions. Superhydrophilic three-dimensional macroporous g-C3N4 was obtained by self-assembly of precursors in aqueous solution followed by thermal polycondensation. By adding various weight ratios (0.15%, 1.5% and 7.5%) of CUPC, the composites exhibited a strong absorption in the region of red and infrared light. The CUPC-CN 7.5% composite achieved a photothermal conversion efficiency of 98.5% in nanofluids with an interfacial solar evaporation efficiency of 93.6% for artificial sea water and 98.7% for deionized water, which are among the highest reported to date. Besides, the composite materials demonstrated superior water purification capabilities by decomposing dye molecules and E. coli bacteria in aqueous solution. Our work established a novel approach for the development of multifunctional interfacial evaporators based on macroporous organic semiconductor heterostructures.

Harnessing Photocatalytic and Photothermal Effects of C-Doped Graphitic Carbon Nitride for Efficient Bacterial Disinfection.

In this work, the photocatalytic and photothermal effects of carbon-ring-doped graphitic carbon nitride materials against bacteria were systematically studied in a dispersed solution and on a membrane. C-doped graphitic carbon nitride materials C-CN 0.15, 1.5, and 7.5 were synthesized by mixing urea precursor with 0.15, 1.5, and 7.5 wt % glucose. With the increase in the doping level, the photothermal effect was clearly enhanced while the generation of reactive oxygen species (ROS) was slightly inhibited. With exposure to irradiation under a 100 mW cm-2 Xeon lamp with a cutoff filter (λ ≥ 420 nm), the ROS concentration of C-CN 1.5 increased 30% in the dispersed solution and its temperature increased about 10 °C in the dispersed solution and on the membrane compared to that of pristine carbon nitride. As a result, the bactericidal activity of C-CN 1.5 was improved by an order of magnitude in the dispersed solution and more than 2 orders of magnitude on the membrane immersed in a solution at 40 °C. To investigate the fundamental light absorption process on the membrane, an optical model using the finite-difference time-domain method was developed based on the topography of the membrane. The simulation results may explain that although C-CN produces more ROS in a solution; however, with a larger extinction coefficient, the power absorption is lower near the surface of the membrane. The ROS production is therefore inhibited and the bactericidal activity is dominated by the photothermal effect. Our experimental and simulation results provide a basis for designing high-performance photoactive disinfection materials and surfaces.