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In this study, hierarchical SnO2@MOx (SnO2@NiO, SnO2@Co3O4, and SnO2@MnO2) heterostructures grown on carbon cloth (CC) for high performance supercapacitors were fabricated by a two-step solution-based method involving a hydrothermal process and a chemical bath deposition, which utilizes the better electronic conductivity of SnO2 nanosheets as the supporting backbone to deposit MOx for supercapacitor electrodes. Particularly, the as-formed SnO2@MOx heterostructure electrodes showed better electrochemical performance than bare SnO2 nanosheets. Remarkably, the SnO2@MnO2 heterostructure electrode showed the highest discharge areal capacitance (980 mF cm−2 at 1 mA cm−2), good rate capability (still 767 mF cm−2 at 20 mA cm−2), and excellent cycling stability (∼21.9% loss after 6000 repetitive cycles at a charge–discharge current density of 1 mA cm−2). The enhanced pseudocapacitive performance was mainly attributed to its unique hybrid structure, which provides fast ion and electron transfer, a large number of active sites, and good strain accommodation. The excellent electrochemical performance of the as-obtained heterostructures will undoubtedly make these hybrid structures attractive for high performance supercapacitors with high power and energy densities.

Heterostructured ZnO/ZnS nanoforests are prepared through a simple two-step thermal evaporation method at 650 °C and 1300 °C in a tube furnace under the flow of argon gas, respectively. A metal catalyst (Au) to form a binary alloy has been used in the process. The as-obtained ZnO/ZnS products are characterized by using a series of techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersion X-ray spectroscopy (EDS), Raman spectroscopy and photoluminescence. A possible growth mechanism is temporarily proposed. The hybrid structures are also directly functionalized as supercapacitor (SC) electrodes without using any ancillary materials such as carbon black or binder. Results show that the as-synthesized ZnO/ZnS heterostructures exhibit a greatly reduced ultraviolet emission and dramatically enhanced green emission compared to pure ZnO nanorods. The SCs data demonstrate high specific capacitance of 217 mF cm(-2) at 1 mA cm(-2) and excellent cyclic performance with 82% capacity retention after 2000 cycles at a current density of 2.0 mA cm(-2).

Hybrid α-Fe2O3@NiO heterostructures are successfully anchored on a carbon cloth by a facile hydrothermal approach. α-Fe2O3 nanorods are used as the conducting scaffolds to support NiO nanosheets. The as-prepared heterostructures are characterized by series of techniques and directly functionalized as the supercapacitors (SCs) without using any ancillary materials such as carbon black or the binders. The SCs demonstrate high areal capacitance of 557 mF/cm2 and excellent cyclic performance with nearly 96.2% capacity retention after 3000 cycles at a current density of 1 mA/cm2. The excellent electrochemical performance can be attributed to a rational combination of two electrochemical active materials. Besides, the hybrid heterostructure can be used as a high performance recyclable photocatalyst under visible light irradiation, which can photodegrade Congo red (CR) with the degradation rate of 98% after 30 min, it demonstrates potential applications in wastewater treatment and energy storage devices.

This paper reports the successful synthesis, structural and optical characterizations of ultra-long germanium oxide (GeO 2 ) nanowires. The ultra-long GeO 2 nanowires were synthesized by facile and simple thermal evaporation process using high-purity Ge powder on Au/Si substrate at 1200 °C. The prepared nanowires were investigated by various techniques in terms of their morphological, structural, compositional and optical properties. By detailed morphological, structural and compositional studies, it is confirmed that the prepared GeO 2 nanowires are pure, grown in very high density, and possessing well-crystallinity. A VLS growth mechanism is proposed for the formation of as-prepared GeO 2 nanowires. The optical properties of the as-prepared nanowires were conducted by room-temperature photoluminescence (PL), revealing that the nanowires exhibited a prominent UV emission peak centered at 411 nm and a weak green emission peak at 526 nm, and hence demonstrating good optical properties with fewer deep-level defects.

alpha-Fe2O3 nanorods are controlled prepared by a facile hydrothermal process followed by a calcination treatment. The experiment results indicate that the morphology of the as-obtained product depends greatly on the quantity of NaOH. The photocatalytic performances of the as-prepared samples were evaluated by photocatalytic decolorization of Congo red solution at ambient temperature. The results indicate that the photocatalytic activity of the alpha-Fe2O3 nanorods is superior to alpha-Fe2O3 nanoparticles and microplates, revealing the versatile potential applications of the product in wastewater purifications.

Novel SnO 2 assembles by many nanosheets are successfully synthesized on a flexible carbon cloth through a chemical vapor deposition (CVD) method at 750 °C. The as-prepared products are characterized by using a series of test techniques, including scanning electron microscope (SEM), X-ray diffraction (XRD), Raman spectrum and the spectrophotometer. A possible growth mechanism is temporarily proposed. Photoluminescence (PL) spectrum of the as-prepared SnO 2 product shows a weak blue emission peak at 436 nm and a strong green emission peak centered at 526 nm, which may be ascribed to the defects associated with the structures.

In this work, ZnO nanorods are obtained through a facile hydrothermal route. The structure and morphology of the resultant products are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The experimental results indicated that the as-synthesized ZnO nanorods have an average diameter of approximate 100 nm. A possible growth mechanism for ZnO nanorods was proposed based on the experimental results and found that Zn powder plays a critical role for the morphology of the products. Room temperature photoluminescence property of ZnO nanorods shows an ultraviolet emission peak at 390 nm.

Large scale ZnO microflowers assembled by numerous nanosheets are synthesized through a facile and effective hydrothermal route. The structure and morphology of the resultant products are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Photocatalytic properties of the as-synthesized products are also investigated. The results demonstrate that eosin red aqueous solution can be degraded over 97% after 110 min under UV light irradiation. In addition, methyl orange (MO) and Congo red (CR) aqueous solution degradation experiments also are conducted in the same condition, respectively. It showed that nanosheet-assembled ZnO microflowers represent high photocatalytic activities with a degradation efficiency of 91% for CR with 90 min of irradiation and 90% for MO with 60 min of irradiation. The reported ZnO products may be promising candidates as the photocatalysts in waste water treatment.

Hierarchically assembled SnO2 microflowers were synthesized by a facile hydrothermal process. Field emission scanning electron microscope results showed these hierarchical nanostructures were built from two dimensional nanosheets with the thicknesses of about 50 nm. Photoluminescence spectrum of the as-obtained products demonstrated a strong visual emission peak at 564 nm. The photochemical measurement results indicated that the as-prepared sample exhibits excellent photocatalytic performance. These three dimensional SnO2 hierarchical nanostructures may have potential applications in waste water purification.