No abstract

No abstract

Photocatalysis provides an attractive strategy for synthesizing H2O2 at ambient condition. However, the photocatalytic synthesis of H2O2 is still limited due to the inefficiency of photocatalysts and decomposition of H2O2 during formation. Here, we report SnO2-TiO2 heterojunction photocatalysts for synthesizing H2O2 directly in aqueous solution. The SnO2 passivation suppresses the complexation and decomposition of H2O2 on TiO2. In addition, loading of Au cocatalyst on SnO2-TiO2 heterojunction further improves the production of H2O2. The in situ electron spin resonance study revealed that the formation of H2O2 is a stepwise single electron oxygen reduction reaction (ORR) for Au and SnO2 modified TiO2 photocatalysts. We demonstrate that it is feasible to enhance H2O2 formation and suppress H2O2 decomposition by surface passivation of the H2O2-decomposition-sensitive photocatalysts.

Background β‐cyclodextrin modified g‐C3N4 (β‐CD/g‐C3N4) nanosheets were successfully synthesized and developed as a novel drug carrier of doxorubicin hydrochloride (DOX•HCl). The prepared samples were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The drug‐loading and drug release was measured by a UV–visible spectrophotometer. Moreover, cell viability tests were carried out to evaluate the inhibition ratio of β‐CD/g‐C3N4‐DOX•HCl and bulk g‐C3N4‐DOX•HCl. Results The FTIR result confirmed that β‐CD and g‐C3N4 are linked by hydrogen bonds. The XRD and TEM results showed that β‐CD/g‐C3N4 has nanosheet structure with size range 150–300 nm. The drug‐loading ratio rises sharply in the first 14 h and reaches a maximum of 93%. Moreover, β‐CD/g‐C3N4 nanocomplex showed a pH‐responsive DOX•HCl release with a release ratio of 80% at pH = 5, which is two times higher than that of bulk g‐C3N4. Cell viability tests demonstrated that the β‐CD/g‐C3N4‐DOX•HCl exhibit a higher inhibition ratio on MG63 cells than bulk g‐C3N4‐DOX•HCl. Conclusion β‐CD/g‐C3N4 nanocomplex achieves an ultrahigh drug‐loading capacity and pH‐responsive release and visualization of the cell phagocytic process. The results indicate that the β‐CD/g‐C3N4 nanocomplex can be developed as a promising luminescence carrier for drug delivery. © 2018 Society of Chemical Industry

This work investigates shear fracture behavior occurring in a titanium alloy cylinder internally filled with high explosives through the use of photonic Doppler velocimetry(PDV) array, high-speed framing camera and soft capture tank. The real-time velocity profiles diagnosed by PDV array display from overlapping to scattering, corresponding to the cylinder from uniform expansion to onset of fracture. In addition to the general findings obtained from individual diagnostics, combined analysis from the experimental measurements determines sliding velocity between sheared cracks and the overall adiabatic shear failure process of the metal cylinder is discussed.

Photocatalytic hydrogen peroxide (H2O2) production has attracted considerable attention as a renewable and environment-friendly method to replace other traditional production techniques. The performance of H2O2 production remains limited by the inertness of graphitic carbon nitride (CN) towards the adsorption and activation of O2. In this work, a photocatalyst comprising of β-cyclodextrin (β-CD)-modified CN with supporting Au co-catalyst (Au/β-CD-CN) has been utilized for effective H2O2 production under visible light irradiation. The static contact angle measurement suggested that β-CD modification increased the hydrophobicity of the CN photocatalyst as well as its affinity to oxygen gas, leading to an increase in H2O2 production. The rate of H2O2 production reached more than 0.1 mM/h under visible-light irradiation. The electron spin resonance spectra indicated that H2O2 was directly formed via a 2-electron oxygen reduction reaction (ORR) over the Au/β-CD-CN photocatalyst.

No abstract

No abstract