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[Display omitted] Photocatalytic reduction of Cr(VI) in water environments attracts more attention; however, the mechanisms involved in this process have not been clearly elucidated yet. In this study, the photocatalytic reduction of Cr(VI) by polydopamine modified Bi 2.15 WO 6 (PDA/BWO) under visible light was conducted. Kinetics results show that PDA apparently accelerates the reduction of Cr(VI). The quasi-first-order kinetic constant of Cr(VI) reduction by 5PDA/BWO is 70.0 times that of the original BWO, reaching 0.070 min−1. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Raman analyses confirm the formation of ligand-to-metal charge transfer (LMCT) complex [Bi(III) O C] between PDA and BWO. The formed Bi(III) O C complex enhances visible light response and narrows the bandgap of PDA/BWO. The photoelectrochemical and photoluminescent characterization further reveals that the formed Bi(III) O C complex inhibits the recombination of carriers, thus enhancing the photocatalytic reactivity of PDA/BWO. Electrons, are derived from three paths, including dye sensitization, LMCT and bandgap excitation, contribute to Cr(VI) reduction by PDA/BWO. This study provides new insights on the paths of Cr(VI) reduction by PDA/BWO under visible light. [ABSTRACT FROM AUTHOR]

Highlights: [•] Monodisperse Au–SiO2 composite nanospheres were synthesized through a one-pot method. [•] The morphologies and sizes of the composite nanospheres were both controllable. [•] The nanospheres displayed different SERS effects by adjusting their morphologies. [•] The products showed high catalytic activity in catalytic reduction of 4-nitrophenol. [ABSTRACT FROM AUTHOR]

Highlights: [•] The disk-like microparticles were self-assembled from monodispersed hybrid nanoparticles. [•] These microparticles could be obtained in large amount under a simple mild condition. [•] These particles could be used to biomimetic design of the superhydrophobic surface of lotus leaf. [•] The static contact angle of water on the micro/nano hierarchical structured surface was 168.8°. [•] The click reaction further simplified surface modification under mild condition. [ABSTRACT FROM AUTHOR]

Abstract: An easy, novel route to prepare Janus nanoparticles and nano-bowls with tunable shapes has been developed. This approach uses a new kind of monodisperse vinyl-silica nanoparticles as templates to obtain large amounts of uniform Janus particles and nano-bowls (several grams). The efficient method adopts water-based hydrolysis-condensation and seed-emulsion polymerization. The uniform Janus nanoparticles and nano-bowls will display wide potential applications in many fields, such as: chemical sensors, construction of complex superstructures and nano-bioreactors. [Copyright &y& Elsevier]