Highly dispersed NiS2 quantum dots as a promising cocatalyst bridged by acetylene black significantly improved the photocatalytic H2 evolution performance of g-C3N4 nanosheets.

In this work, ternary nanocomposite (CNs-AB/NiS2) as a novel efficient H2 evolution photocatalyst without the use of noble metals was successfully synthesized by depositing acetylene black (AB) and ultra-fine NiS2 nanoparticles on the surface of CNs (g-C3N4) through ultrasonic dispersion and chemical vapor deposition methods, respectively. It was revealed that the loaded AB and NiS2 nanoparticles have significantly improved the photocatalytic H2 evolution efficiency of the CNs by improving the photogenerated electron-hole pair separation, visible light absorption and hydrogen evolution kinetics. Besides acting as a cocatalyst, AB served as a conductive electron bridge between CNs and NiS2, which accelerated the effective transfer of electrons from CNs to NiS2 and improved the H2 evolution kinetics of the NiS2 cocatalyst. The H2 evolution experiments revealed that the ternary photocatalyst CNs-AB/NiS210 displayed a H2 evolution rate of up to 2434.85 µmoL g-1 h-1, which was a 1.41 times enhancement compared to that of the binary composite CNs-NiS210 and was 12.43 times higher than that of the pure CNs. Moreover, the ternary photocatalyst CNs-AB/NiS210 not only exhibited excellent photocatalytic activity and stability in the tests, but provided a novel idea for the development of high-efficiency catalysts free of noble metals as well.

Multifunctional nanoplatform based on g-C3N4, loaded with MnO2 and CuS nanoparticals for oxygen self-generation photodynamic/photothermal synergistic therapy.

Photodynamic therapy (PDT) and photothermal therapy (PTT) are both promising therapeutic approaches for cancer. Unfortunately, the anticancer efficiency of PDT is restricted by the hypoxic tumor microenvironment and the performance of the photosensitizer (PS) while the efficiency of PTT is limited by the penetration depth of NIR light, making it difficult to further improve the efficiency of the treatment. In this paper, we strategically proposed a multifunctional nano-platform based on g-C3N4 and loaded with CuS and MnO2 nanoparticals. Interestingly, the obtained F127@CNs-CuS/MnO2 nano-platform with high singlet oxygen quantum yield and excellent photothermal performance were used in synergistic PTT and PDT therapy to cope with the limitation of single mode cancer treatment under irradiation and has greatly improved the treatment effect. Additionally, MnO2 nanoparticles loaded on the CNs surface could not only generate oxygen to ameliorate hypoxia in the tumor environment by reacting with H2O2 in tumor cells, but also react with the over-expressed reduced glutathione (GSH) in cancer cells to further improve the synergistic therapeutic effect. In the in vitro hepatocarcinoma cell inactivation experiment, the maximum cell inactivation efficiency of the PDT, PTT and PDT/PTT synergistic treatment group reached at 65% (F127@CNs-MnO2), 69.2% (CNs-MnO2) and 88.6% (F127@CNs-MnO2) respectively, which means that the F127@CNs-CuS/MnO2-mediated PTT/PDT synergy anticancer treatment was more effective than single mode therapy. In summary, the innovative multifunctional nanoplatform F127@CNs-CuS/MnO2 used for synergistic PTT and PDT treatment has greatly improved the inactivation efficiency of cancer cells and has provided a new scheme for the treatment of hypoxic tumors.