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Black TiO2owing to its fascinating photocatalytic properties has attracted research interest all around the world. Herein, the template-free hydrothermal method has been used to prepare black-TiO2using different alkaline reagents (NaOH, NH4OH, LiOH, and KOH) to study their effect on the physiochemical properties. XRD, Raman spectroscopy, FESEM, EDX, UV–vis DRS, and PL investigations were carried out and comparatively discussed. The as-prepared black TiO2has been subjected to photocatalytic degradation of methylene blue (MB) under visible light irradiation. Black TiO2prepared from NH4OH displayed superior MB removal compared to others. The exceptional photocatalytic performance is attributed to its smaller band gap and enhanced porosity of the material. Meanwhile, black TiO2prepared from KOH exhibited the least photocatalytic degradation capability due to abundant oxygen vacancies. Furthermore, the proposed mechanism highlights the effect of chemical reagents on the physiochemical properties of black TiO2and describes the cause of poor photocatalytic behavior of KOH-based black TiO2compared to others.

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Development of layered nanostructures with distinct morphology has become an avenue of recent research to engineer targeted properties, especially for electrochemical devices. However, their remarkable characteristics are yet to be exploited for biological applications. In this work, we followed a facile and single-step method and prepared the solution grown zinc vanadium oxide multilayered nanosheets (ZnV2O4MLNs). Field emission scanning electron microscopy shows the presence of nanosheets about 15–20 nm in height, integrated, and overlapped with one another, conferring a layered morphology. The layers are a structural mixture of triangular and hexagonal shapes. The phase pure and highly crystalline ZnV2O4MLNs are investigated as an efficient receptor material for the electrocatalytic binding of glutathione, an important biomolecule involved in many cellular processes. This work is the first report where ZnV2O4MLNs are employed to bind biomolecules. These nanostructured interfaces are expected to increase the effective surface area for detection, improve the planer surface of the sensor, and provide more binding sides for greater sensitivity. The developed sensor enables the sensitive detection of glutathione with outstanding detection limit down to 9 nM and ensures the 100% selectivity at a specific potential when compared to its functional and structural analogues. The study demonstrates the novel multilayer morphology-based interfaces can be a favourable platform to develop immune probes and further establishes their great potential to detect clinical biomolecules and disease biomarkers.

Layered manganese-based cathode materials are of great interest because of their high specific capacities for sodium-ion batteries. However, the Jahn–Teller effect and the inevitable phase transition are detrimental for achieving considerable cycling stability and rate capability. Herein, a P2-type manganese oxide nanoplate cathode material modified by Mo-substitution with an oriented stacking structure and exposed {010} active facets is reported. The manganese oxide nanoplate cathode yields remarkable capacity retention of 86% after 1200 cycles at 10 C (2000 mA g–1). The specific power density is estimated to be as high as 530 W kg–1with a specific discharge capacity 143.9 mA h g–1at 1 C and 89.6% capacity retention up to 100 cycles. The superior electrochemical performances can be attributed to the efficient chemical modification and the unique structural features of the present manganese oxide nanoplate. Mo-modification can endow the manganese oxide cathode with enlarged lattice space and average oxidation state and thus favorable Na+diffusion to inhibit the Jahn–Teller effect and improve the structure stability, thereby achieving an extremely long cycling life. A multilayer oriented stacking nanoplate structure with exposed {010} active facets is also beneficial for providing more surface active sites and shortening the Na+diffusion path, leading to better rate capability.

•Synthesis of differently shaped Au/Cu2O (metal/semiconductor) core/shell nanostructures.•Effect of nanoparticle morphology and shell thickness on optical properties of Au/Cu2O nanostructures.•Correlation of photoluminescence analyses of core/shell nanostructures with their photocatalytic activities.•Nanostructures with more {100} catalytically inactive sites reveal a comparatively sharp emission peak.

Hierarchical nanostructures (Hs) have recently garnered enormous attention due to their remarkable performances in catalysis, electronic devices, energy storage and conversion. Considering the advantage of hierarchical nanostructures, we have formulated a facile and template free method to synthesize novel hierarchical nanospheres (NHNs) of ZnV2O4. Both zinc and vanadium are earth abundant, relatively economical and can offer several oxidation states, which can render a broad range of redox reactions favorable for electrochemical energy storage applications. Keeping these points in mind, we investigated for the first time the electrochemical supercapacitor performance of NHNs. The electrochemical measurements were performed in 2 M KOH solution. The measured specific capacitance of ZnV2O4electrode is 360 F/g at 1 A/g with good stability and retention capacity of 89% after 1000 cycles. Moreover, the hydrogen storage properties of NHNs were measured at 473, 573, and 623 K with an absorption of 1.76, 2.03, and 2.49 wt %. respectively. These studies pave the way to consider ZnV2O4as prospective material for energy storage applications.

We first report the catalyst free growth of indium selenide microwires through a facile approach in a horizontal tube furnace using indium and selenium elemental powders as precursors. The synthesized microwires are γ-phase, high quality, single crystalline and grown along the [112̅0] direction. The wires have a uniform diameter of ∼1 μm and lengths of several micrometers. Photodetectors fabricated from synthesized microwires show reliable and stable photoresponse exhibiting a photoresponsivity of 0.54 A/W, external quantum efficiency of 1.23 at 633 nm with 4 V bias. The photodetector has a reasonable response time of 0.11 s and specific detectivity of 3.94 × 1010Jones at 633 nm with a light detection range from 350 to 1050 nm, covering the UV–vis-NIR region. The photoresponse shown by single wire is attributed to direct band gap (Eg= 1.3 eV) and superior single crystalline quality. The photoresponsive studies of single microwires clearly suggest the use of this new and facile growth technique without using catalysts for fabrication of indium selenide microwires in next-generation sensors and detectors for commercial and military applications.

We have developed a facile, scale up, and efficient method for the preparation of graphitic-C3N4nanofibers (GCNNFs) as electrodes for supercapacitors and photocatalysts. The as-synthesized GCNNFs have 1D structure with higher concentration of nitrogen that is favorable for higher conductivity and electrochemical performance. Secondly, the high surface area of GCNNF provides a large electrode–electrolyte contact area, sufficient light harvesting and mass transfer, as well as increased redox potential. Thus, the GCNNF supercapacitor electrode shows high capacitance of 263.75 F g–1and excellent cyclic stability in 0.1 M Na2SO4aqueous electrolyte with the capacitance retention of 93.6% after 2000 cycles at 1 A g–1current density. GCNNFs exhibit high capacitance of 208 F g–1even at 10 A g–1, with the appreciable capacitance retention of 89.5%, which proves its better rate capability. Moreover, the GCNNF shows enhanced photocatalytic activity in the photodegradation of RhB in comparison to the bulk graphitic-C3N4(GCN). The degradation rate constant of GCNNF photocatalyst is almost 4 times higher than GCN. The enhanced photocatalytic activity of GCNNF is mainly due to the higher surface area, appropriate bandgap, and fewer defects in GCNNF as compared to GCN. As an economical precursor (melamine) and harmless, facile, and template-free synthesis method with excellent performance both in supercapacitors and in photodegradation, GCNNF is a strong candidate for energy storage and environment protection applications.

We report for the first time the synthesis of single crystalline In2Te3nanosheets. Te nanorods were first produced by controlling the reaction kinetics and then In2Te3nanosheets nucleated at the body of Te nanorods in the presence of organic surfactant. The self-assembly and the certain directional growth process of In2Te3on the body of Te nanorods resulted in an ordered nanostring-cluster which subsequently gave split In2Te3nanosheets. The transformation can be attributed to the developed facets and organic surfactants which can greatly enlarge the lateral dimensions and produce nanosheets. The morphology evolution from nanorods to nanosheets is demonstrated with experimental evidence collected viaSEM, TEM and XRD studies. The synthesis of nanorods/nanosheets will supply additional opportunities for the exploration of novel fundamental properties of telluride based chalcogenides materials. Initial hydrogen storage results pave the way for utilizing telluride-based nanostructures for gas storage and gas sensing properties. Also, the photoresponse properties of indium telluride offers good knowledge for the fabrication of nanoscale electronic and optoelectronic devices.