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Electrocatalytic water decomposition is the key to sustainable energy, and the design and synthesis of cost-effective electrocatalysts is the main objective of electrocatalytic water splitting. In this paper, multi-interfacial FeOOH@NiCo2O4 hybrid nanoflowers are prepared through a two-step hydrothermal reaction. In such heterostructures, NiCo2O4 nanoflowers are coated with a layer of FeOOH nanoparticles. In addition, the obtained electrocatalyst could provide abundant electroactive sites and the formation of FeOOH@NiCo2O4 nanointerfaces can also improve the charge transfer rate. As a result, under the HER and OER conditions, the prepared catalysts show an outstanding electrocatalytic performance. Moreover, in a two-electrode water splitting system, the FeOOH@NiCo2O4 heterostructure, as a dual-function electrocatalyst, needs a cell voltage of only 1.58 V at a current density of 10 mA cm-2. This study provides a facile and feasible method to construct different kinds of heterostructures as bifunctional electrocatalysts with multiple interfaces by a simple hydrothermal method.

Currently, one of the major hurdles hindering the clinical applications of photothermal therapy (PTT) and photothermal-chemo combination therapy (PCT) is the lack of highly efficient, readily derived, and irradiation-safe photothermal agents in the biologically transparent window. Herein, we report the first design and rational construction of 0D/2D/0D sandwich heterojunctions for greatly enhanced PTT and PCT performances using 0D N-doped carbon dots and 2D MoS2 nanosheets as the assembly units. The well-matching heterojunctions enabled an additional enhancement in NIR absorbance owing to the carrier injection from carbon dots to MoS2 nanosheets, and achieved a much higher photothermal conversion efficiency (78.2%) than that of single NIR-CDs (37.6%) and MoS2 (38.3%) only. In virtue of the heterojunction-based PTT, complete tumor recession without recurrence or pulmonary metastasis was realized at an ultralow and safe laser exposure (0.2 W cm-2) below the skin tolerance irradiation threshold. Furthermore, by taking advantage of the strong X-ray attenuation and effective drug loading capacity of MoS2 nanosheets, the CT imaging-guided PCT was achieved at 0.1 W cm-2, without inducing noticeable toxic side effects. Our findings can substantiate the potential of a novel 0D/2D heterojunction for cancer theranostics.

Carbon quantum dots (CQDs) have attracted much attention owing to their unique optical properties and a wide range of applications. The fabrication and control of CQDs with organic solubility and long-wavelength emission are still urgent issues to be addressed for their practical use in LEDs. Here, organic-soluble CQDs were produced at a high yield of ∼90% by a facile solvent engineering treatment of 1,3,6-trinitropyrene, which were simultaneously used as the nitrogen and carbon sources. The optical properties of the organic-soluble CQDs (o-CQDs) were investigated in nonpolar and polar solvents, films, and LED devices. The CQDs have a narrow size distribution around 2.66 nm, and can be dispersed in different organic solvents. Significantly, the as-prepared CQDs present an excitation-independent emission at 607 nm with fluorescence quantum yields (QYs) up to 65.93% in toluene solution. A pronounced solvent effect was observed and their strong absorption bands can be tuned in the whole visible region (400-750 nm) by changing the solvent. The CQDs in various solvents can emit bright, excitation-independent, long-wavelength fluorescence (orange to red). Furthermore, benefiting from the unique oil-solution properties, the as-prepared CQDs can be processed in thin film and device forms to meet the requirements of various applications, such as phosphor-based white-light LEDs. The color coordinate for these CQD modified LEDs is realized at (0.32, 0.31), which is close to pure white light (0.33, 0.33).

PtAg alloyed nanostructural catalysts were firstly prepared by co-reduction of AgNO3 and H2PtCl6 precursors in growth solution using a seed-mediated method. By simply changing the molar ratio of the metal precursors, the morphologies of the porous alloyed nanocrystals can be tuned from multipetals to multioctahedra. Simultaneously, the alloy composition can be varied from Pt76Ag24 to Pt66Ag34. The catalytic properties of the prepared PtAg alloyed nanocrystals with a tunable structure and composition were tentatively examined by choosing the reduction of 4-nitrophenol with NaBH4. The reaction rate normalized to the concentration of catalysts was calculated to be 318.9 s(-1) mol(-1) L and 277.4 s(-1) mol(-1) L for Pt70Ag30 and Pt66Ag34 porous catalysts, which is much higher than the pure Pt catalysts. Moreover, PtAg nanostructures can also serve as efficient electrocatalysts toward the methanol oxidation reaction, especially for Pt70Ag30 and Pt66Ag34 porous nanocrystals. The electrocatalytic activity and the durability were both highly enhanced compared to the commercial Pt/C catalyst. In addition, we also investigated the enhancement mechanism.

In this work, a general, facile, successive and eco-friendly method for multilayer nanostructures has been established for the first time. We take full advantage of the structural and compositional character of M1@M2 (M1 = Co, Ni, M2 = Pt/Pd, Pt, Pd and Au) core-shell nanostructures to prepare a series of reusable tremella-like M1@M2@M1(OH)2 three layer core-shell or yolk-shell nanocomposites with a magnetic core, a porous noble metal shell, and an ultrathin cobalt or nickel hydroxide shell. We evaluated their catalytic performance using a model reaction based on the reduction of 4-nitrophenol. These novel M1@M2@M1(OH)2 nanomaterials with a unique internal micro environment promoted the efficiency of the catalytic reaction, prolonged the service life of the catalyst and enhanced the overall activity of the catalyst in the catalytic process. The novel three layer core-shell nanocomposites can be extended to other applications such as biomedical detection, energy conversion and storage systems.

Novel hierarchical heteronanostructures of ZnO nanorods/ZnS·(HDA)0.5 (HDA = 1,6-hexanediamine) hybrid nanoplates on a zinc substrate are successfully synthesized on a large scale by combining hydrothermal growth (for ZnO nanorods) and liquid chemical conversion (for ZnS·(HDA)0.5 nanoplates) techniques. The formation of ZnS·(HDA)0.5 hybrid nanoplates branches takes advantage of the preferential binding of 1,6-hexanediamine on specific facets of ZnS, which makes the thickening rate much lower than the lateral growth rate. The ZnS·(HDA)0.5 hybrid nanoplates have a layered structure with 1,6-hexanediamine inserted into interlayers of wurtzite ZnS through the bonding of nitrogen. The number density and thickness of the secondary ZnS·(HDA)0.5 nanoplates can be conveniently engineered by variation of the sulfur source and straightforward adjustment of reactant concentrations such as 1,6-hexanediamine and the sulfur source. The fabricated ZnO/ZnS·(HDA)0.5 heteronanostructures show improved electrochemical catalytic properties for hydrazine compared with the primary ZnO nanorods. Due to its simplicity and efficiency, this approach could be similarly used to fabricate varieties of hybrid heterostructures made of materials with an intrinsic large lattice mismatch.

Pt-based nanocomposites have been of great research interest. In this paper, we design an efficient MO/rGO/Pt sandwich nanostructure as an anodic electrocatalyst for DMFCs with combination of the merits of rigid structure of metallic oxides (MOs) and excellent electronic conductivity of reduced oxidized graphene (rGO) as well as overcoming their shortcomings. In this case, the CeO(2)/rGO/Pt sandwich nanostructure is successfully fabricated through a facile hydrothermal approach in the presence of graphene oxide and CeO(2) nanoparticles. This structure has a unique building architecture where rGO wraps up the CeO(2) nanoparticles and Pt nanoparticles are homogeneously dispersed on the surface of rGO. This novel structure endows this material with great electrocatalytic performance in methanol oxidation: it reduces the overpotential of methanol oxidation significantly and its electrocatalytic activity and stability are much enhanced compared with Pt/rGO, CeO(2)/Pt and Pt/C catalysts. This work supplies a unique MO/rGO/Pt sandwich nanostructure as an efficient way to improve the electrocatalytic performance, which will surely shed some light on the exploration of some novel structures of electrocatalyst for DMFCs.

Pt-filled porous LaNiO₃ cubes are prepared through a facile route. The characterizations reveal that large numbers of pores (9-10 nm) are distributed homogeneously in porous LaNiO₃ cubes. The Pt nanoparticles residing in the pores of porous LaNiO₃ cubes are about 5 nm in size. The investigation on the electrocatalytic activity reveals that electrocatalytic activity of the obtained Pt loaded porous LaNiO₃ nanocubes exhibit a significantly improved electrochemical active surface area (EASA) and a remarkably enhanced electrocatalytic performance toward methanol oxidation. The results are significant for improving the efficiency of Pt-based catalysts for DMFCs as well as the applications of perovskite compounds.

Uniform porous three-dimensional nanoarchitectures of α-Fe(2)O(3) with high yield have been synthesized by a route based on a Ni(2+)/surfactant system. The obtained α-Fe(2)O(3) has a flue-like porous morphology with a rough surface. What is more, spatially ordered nodes and meshes are presented in these networks. By adjusting the experimental parameters such as temperature, reaction time, proportion of Ni(2+)/PVP and types of cation, we can control the morphology of the samples well. A possible formation mechanism is proposed to explain the growth of the flue-like nanostructures. The obtained flue-like porous α-Fe(2)O(3) has a large specific surface area of 88.82 m(2) g(-1). It exhibits significantly enhanced visible-light-driven photocatalytic performance in the degradation of methylene blue, compared with α-Fe(2)O(3) nanoparticles. This work not only enriches the synthesis methods of porous architectures, but also facilitates the applications of α-Fe(2)O(3) in the fields of water treatment, sunlight utilization and so forth.

In this paper, we successfully fabricate Ti(iv) doped WO₃ nanocuboids with controlled Ti(iv) contents through a facile, mild, aqueous-phase route. The characterizations clearly exhibit the optimum amount of the Ti(iv) dopant in under these conditions. The obtained photocatalyst shows excellent visible-light-driven photocatalytic performance. It can decompose an organic dye within 70 min under visible-light irradiation. Such a large activity enhancement probably arises from the change of band structure. The results provide an efficient route for the design of photocatalysts with improved visible-light-driven photocatalytic activity as well as a promising material for use in solar cells, nanodevices, and other applications.

In this paper, single-crystalline α-Fe2O3 oblique nanoparallelepipeds are fabricated in high yield via a facile surfactant-free hydrothermal method, which involves oriented aggregation and Ostwald ripening. The obtained nanocrystals have exposed facets of {012}, {01-4} and {-210} with a rhombohedral α-Fe2O3 structure. The gas sensors based on the as-synthesized α-Fe2O3 nanostructures exhibit high sensitivity, short recovery time, and good reproducibility in ethanol and acetone. The superiority of the gas-sensing properties of the obtained nanostructures should be attributed to the surface structure of the nanocrystals. The as-prepared α-Fe2O3 nanocrystals are significant for exploiting their other applications in the future.

In this paper, we report on the fabrication of a novel rutile TiO(2) architecture consisting of nanorods with {110} exposed facets through a simple hydrothermal method without using any templates. An outside-in ripening mechanism is proposed to account for the formation of the TiO(2) architectures.The formation of the TiO(2) architectures can be attributed to the Ostwald step rule and highly acidic medium. Significantly, the current method is suitable for high-yield (>98%) production of the TiO(2) architectures with nearly 100% morphological yield. This research provides a facile route to fabricate rutile TiO(2) with three-dimensional microstructures based on nano units. It is easy to realize their industrial-scale synthesis and application because of the simple synthesis method, low cost, and high yield.