Graphitic C3N4 (g-C3N4), as an advanced metal free photocatalyst, is known to be poorly exfoliated and dispersed in water from its powder form which has a layered structure, the intrinsic plane structure is not destroyed, and this has largely limited its application. In this work, we report our progress on successful sonication exfoliation of g-C3N4 nanosheets in graphene oxide (GO) aqueous solution. By making use of the substrate character of GO, g-C3N4 nanosheets of unvaried intrinsic structure were exfoliated and anchored on the GO surface, resulting in a GO/g-C3N4 hybrid. Moreover, the photocurrent of the hybrid was largely reinforced at the optimal weight fraction of GO. As a result, the corresponding photocatalytic performance of the hybrid with optimized photocurrent character was largely improved.

Dynamic molecular crystals are of high interest due to their potential applications. Herein we report the reversible on-off switching of single-molecule magnet (SMM) behavior in a [Mo(CN)] based molecular compound. Upon dehydration and rehydration, the trinuclear MnMo molecule [Mn(L)(HO)][Mo(CN)]·2HO (1) undergoes reversible crystal-to-crystal transformation to a hexanuclear MnMo compound [Mn(L)(HO)][Mn(L)][Mo(CN)] (2). This structural transformation involves the breaking and reforming of coordination bonds which leads to significant changes in the color and magnetic properties. Compound 1 is an SMM with an energy barrier of 44.9 cm, whereas 2 behaves as a simple paramagnet despite its higher ground state spin value. The distortion of the pentagonal bipyramidal geometry of [Mo(CN)] in 2 disrupts the anisotropic exchange interactions that lead to SMM behavior in 1.

Bi 2 S 3 nanowire/CdS nanoparticle heterostructure has been designed and constructed through an easy wetchemistry approach at 140 °C for 8 h. The product is mainly composed of Bi 2 S 3 nanowires, several hundred nanometers long and 10 nm wide, and epitaxially grown triangle-like CdS nanoparticles with size of 20 nm at their surfaces. A possible sequential deposition growth mechanism is proposed on the basis of experimental results to reveal the formation of the nanoscale heterostructure. Under the irradiation of UV light, the as-prepared nanoscale Bi 2 S 3 /CdS heterostructure exhibits enhanced photochemical efficiency that can be mainly attributed to the microstructure of the product. In the nanoscale heterostructure, the CdS nanoparticle not only determines the overall band gap energy, but also controls the charge carrier transition, recombination, and separation, while the Bi 2 S 3 nanowire serves as support for the CdS nanoparticle, defines the specific surface area of the product and thus influences the photocatalytic activity. The effects of reaction parameters on the structure and photocatalytic activity of the final product are also discussed.

Nanocubes and hollow cubic microcages of FeCo alloy have been synthesized in large scale by reduction of aqueous Fe 2+ and Co 2+ with hydrazine in the presence of poly(ethylene glycol) and cyclohexane at a relative low temperature, which were confirmed by X-ray powder diffraction, transmission electron microscopy, and scanning electron microscopy. The morphology and dimensions of FeCo alloy nanocrystals could be controlled by the reaction conditions such as the concentrations of cyclohexane and PEG-400, reaction time, and the molar ratio of Fe 2+ to Co 2+ in the solution. The concentration of iron in these particles could be varied between 17% and 56%. The highest magnetization of 211.9 emu/g was recorded for 68 ( 6 nm Fe 50 Co 50 nanocubes. The work demonstrates that shape and size-controlled synthesis can offer a simple solution to fabricate magnetic FeCo nanocubes that are promising for single nanoparticle recording and for high performance exchange-spring nanocomposite magnetic applications.

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Reversible controlling and switching of magnetic bistability remains relatively difficult. Here, reversible on−off switching of a hysteretic spin transition in a Co II complex via a single-crystal to single-crystal (SC-SC) transformation during dehydration and rehydration was reported. Upon dehydration, a switching from a basically low spin state to an abrupt and hysteretic spin crossover (SCO) with broad hysteresis loops was achieved. Hysteretic and anisotropic crystal lattice expansion or contraction in the spin transition temperature range was also observed in the dehydrated complex. The magneto−structural relationship in this system was established on the basis of detailed structure analyses on both the hydrated and dehydrated examples over a wide range of temperatures. The elimination of guest internal pressure, the tuning of the supramolecular interactions, and the strong electron−lattice coupling should be responsible for the hysteretic SCO in the dehydrated complex.