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TiO2-based nanosheets (TNS) modified with Fe2O3 and Y2O3 particles (Fe2O3/Y2O3@TNS), possessing a laminar structure with large specific surface area of 382 m2 g−1, were synthesized via a one-pot hydrothermal method. The optimized Fe2O3/Y2O3@TNS (Fe/Y/Ti = 0.1 at%: 0.75 at%: 1) exhibited high photocatalytic efficiency due to the synergistic effect, and the photodegradation rate towards RhB and K2Cr2O7 solutions were 5.82-fold and 2.35-fold higher, respectively, as compared to TNS under visible light. Simultaneous photocatalytic degradation in the Cr(VI)–phenol coexisting system revealed that there was synergism between Cr(VI) reduction and phenol degradation for promoting photocatalytic efficiency. Besides, Fe2O3/Y2O3@TNS demonstrated strong adsorption and excellent photocatalytic regeneration performance for high-chroma crystal violet (CV), showing potential application in the removal of organic or inorganic pollutants. Based on photoluminescence (PL) spectra and photocurrent (SPC) methodology, the separation efficiency of photogenerated e−–h+ pairs could be significantly strengthened. A possible mechanism for enhanced photocatalytic efficiency under visible light was proposed. [ABSTRACT FROM AUTHOR]

ZnTi-LDHs with different morphologies were successfully fabricated via a surfactant-assisted hydrothermal method. With the help of surfactants, we focus on exploring the morphology control of ZnTi-LDHs, and the promotion effects on their photocatalytic performances. Experimental results showed that the type of surfactant affected the morphology of ZnTi-LDHs. With the help of an anionic surfactant (sodium dodecyl sulfate), ZnTi-LDHs with flower-like structures were obtained by the self-assembly of sheets. Triblock copolymers (P-123) led to the formation of ZnTi-LDH particles assembled together. Both a cationic surfactant (CTAB) and non-ionic surfactant (PVP) have less guiding effect on the growth of ZnTi-LDHs. The self-assembled ZnTi-LDH particles exhibit excellent photocatalytic performances in methyl orange degradation when P-123 is added into the solution as a surfactant. The formation mechanism of ZnTi-LDHs with different surfactants has been proposed. This study proposes a common mechanism of surfactants in the formation of ZnTi-LDHs, which is instructive for the further design of LDHs with controlled morphology. [ABSTRACT FROM AUTHOR]

As a two-dimensional (2D) material, molybdenum disulfide (MoS2) exhibits unique electronic and optical properties useful for a variety of optoelectronic applications including light harvesting. In this article, we review recent progress in the synthesis, properties and applications of MoS2 and related heterostructures. Heterostructured materials are developed to add more functionality or flexibility compared to single component materials. Our focus is on their novel properties and functionalities as well as emerging applications, especially in the areas of light energy harvesting or conversion. We highlight the correlation between structural properties and other properties including electronic, optical, and dynamic. Whenever appropriate, we also try to provide fundamental insight gained from experimental as well as theoretical studies. Finally, we discuss some current challenges and opportunities in technological applications of MoS2. [ABSTRACT FROM AUTHOR]

The free volumes and proton conductivities of Nafion membranes were investigated at different humidities by positron annihilation lifetime spectroscopy (PALS) and using an electrochemical workstation, respectively. The results showed that the variation in o-Ps lifetime τo-Ps was closely associated with the microstructure evolution and the development of hydrophilic ion clusters in Nafion membranes as a function of water uptake, regardless of metal oxide additives. In particular, with increasing relative humidity, the maximum value of τo-Ps in the Nafion membranes corresponded to the formation of numerous water channels for proton transportation. Numerous well-connected water channels in Nafion–TiO2 hybrid membranes could be formed at a much lower relative humidity (∼40% RH) than in the pristine one (∼75% RH), due to the better water retention ability of the Nafion–TiO2 membranes. Further, a percolation behavior of proton conductivity at high water uptake in Nafion membranes was observed, which showed that the percolation of ionic-water clusters occurred at the water uptake of ∼4.5 wt%, and ∼6 wt% was basically enough for the formation of a well-connected water channel network. [ABSTRACT FROM AUTHOR]

A piezoelectric catalyst of the MoS 2 @TNr composite (MoS 2 nanosheets composited with TiO 2 nanorods) was synthesized by a two-step hydrothermal method, and can be recycled and reused as an advanced anode material for supercapacitors. In the dark, the MoS 2 @TNr composite exhibited ultra-fast piezoelectric catalytic performance and good cycle stability on dye degradation; within 10 min, nearly all rhodamine B (50 mL, 20 ppm) was removed from the solution with the assistance of magnetic stirring. After the 5 cycle degradation reaction, the catalyst was reclaimed and applied to electrochemical testing, which showed better supercapacitor capacitance properties than the fresh catalyst due to the introduction of oxygen vacancies generated from the piezoelectric degradation process. The reclaimed catalyst demonstrated an excellent specific capacitance of 249 F g -1 at 1 A g -1 , and 92% capacitance retention after 10 000 cycles. Furthermore, as the current density increased to 30 A g -1 , the capacitance could maintain 58% of the initial value. Thus, it can be concluded that the abandoned catalysts may serve as a potential electrode material for energy storage; simultaneously, the reutilization could eliminate secondary pollution and decrease the energy consumption in efficiency., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)