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The construction of a heterogeneous structure on an electrode can enhance its absorption energy, thereby improving ionic diffusion and reaction kinetics. Herein, hyperdispersed VO2/V8C7 nano‐heterostructures anchored on carbon nanofibers (VO2/V8C7@CNF), which are further utilized as a lithium anode are successfully developed. The self‐supported VO2/V8C7@CNF electrode features a synergistic effect, resulting from its well‐dispersed nano‐heterostructure, induced hetero‐interfacial electric field, and conspicuous lithiophilicity. This anode thus facilitates rapid Li+ ions diffusion and charge transfer, resulting in high‐rate performance and uniform Li deposition. It exhibits a reversible specific capacity of as high as 674.8 mA h g−1 at a current density of 0.1 A g−1 and maintains a high‐rate capability of 205.3 mA h g−1 at a current density of as high as 5.0 A g−1 even after undergoing 1000 charge/discharge cycles. The Li‐ion nucleation overpotential on this anode is significantly reduced to 27 mV. The hyperdispersed nano‐heterostructure strategy offers a universal blueprint for the fabrication of high‐performance anodes not only for lithium and other batteries. [ABSTRACT FROM AUTHOR]

It is still a big challenge to synthesize well-defined nano-heterostructures by wet chemistry method, as realizing accurate control on each nanocrystal is difficult in solution. In this contribution, the cobalt oxide-phosphomolybdic acid (CoO-PMA) hetero-nanosheets are synthesized by introducing PMA clusters, which have comparable size to the crystal nuclei of CoO. Time-dependent experiments reveal how the nanosheets form: nanoclusters and nuclei first assemble into nanowires and then grow into nanosheets with the assistance of oleylamine. And the results of electrospray ionization ion-trap time-of-flight mass spectrometry (ESI-IT-TOF-MS) also demonstrate the existence of PMA clusters in the final product. Moreover, in this strategy, both metal oxides and nanoclusters can be extended, leading to a series of ultrathin heterostructures. Finally, the CoO-PMA hetero-nanosheets exhibit excellent property in the oxidation of thioether at room temperature, making it a potential catalyst in desulfurization.

The coupling of TiO2 and SrTiO3 through elaborate bandgap engineering can provide synergies for highly efficient photocatalysts. To further improve the separation between photogenerated electrons and holes, a nano‐heterostructured combination of semicrystalline SrTiO3 (S‐SrTiO3) and anatase TiO2 nanoparticles is designed, and an optimized interface is achieved between uniformly grown S‐SrTiO3 and metal organic framework (MOF)‐derived anatase TiO2 through a controlled hydrothermal process. Besides tuning of the bandgap and broadening of the absorption spectral range, S‐SrTiO3 particles alleviate charge carrier recombination benefiting from the coupling of the semicrystalline SrTiO3 around the interface. Additionally, highly dispersed S‐SrTiO3 on TiO2 provides a good spatial distribution of active sites and the abundant carbon remained from MOF may reduce charge transport resistance. Moreover, the rapid transfer within the nano‐heterostructure promotes the separation of the photogenerated charge carriers. With the above predominant architecture, when used as a photocatalyst, the as‐synthesized S‐SrTiO3/TiO2 heterostructure exhibits exceptionally high photocatalytic performance of 13 005 µmol h–1 g–1 for H2 production, exceeding most oxide‐based photocatalysts reported. This study might provide mechanistic insights into a new perspective for the design and preparation of photocatalysts with novel structure and enhanced catalysis activity. [ABSTRACT FROM AUTHOR]

Exploiting efficient catalysts is of interest for solar-driven water splitting. Herein, a novel NiWO 4 /CdS nanosheets-on-nanorods direct Z-Scheme heterostructure was developed by using a facile in-situ approach. The optimized NiWO 4 /CdS heterostructure shows a H 2 evolution rate of 26.43 mmol g−1 h−1 exceeding that of bare CdS by more than 75 folds. Systematic investigations reveal the nanostructures with numerous active sites, intimate contact interface, and enhanced charge separation rate synergistically account for the outstanding performance of the NiWO 4 /CdS. Moreover, the band structures were detailedly analyzed and the tentative photocatalytic mechanism was proposed, which could contribute to deeply understanding the catalytic process and guide the synthesis of the efficient heterostructure. These findings and strategies may have great significance in promoting the development of highly efficient and low-cost photocatalysts. [Display omitted] • A novel NiWO 4 /CdS Z-scheme heterostructure was first constructed by using a facile approach. • The NiWO 4 /CdS exhibits a H 2 evolution rate of 26.43 mmol g−1 h−1 far acceding that of CdS. • The good performance was attributed to the formation of the well-defined heterostructure. • The band energy level and photocatalytic mechanism were detailedly investigated. [ABSTRACT FROM AUTHOR]

The n-ZnO/n-SnO 2 nano-heterostructures surrounded by high-energy facets have been designed and synthesized via a simple two-stage route and used as functional materials of chlorine gas sensor. The composition, morphology and structure of ZnO–SnO 2 nano-heterostructures are characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). It is found that both the SnO 2 octahedra nanoparticles and the ZnO–SnO 2 nano-heterostructures are surrounded by high-energy (221) facets. The sensor with the ZnO–SnO 2 nano-heterostructure nanoparticles presents a much higher response (230.52) to Cl 2 (upgrade to 50 times) than that of the sensor with the pure SnO 2 nanoparticles. Moreover, a new and reasonable method is used to calculate the detection limit of two sensors. The sensor with 10% ZnO–SnO 2 sample (ZnO: SnO 2 = 10%, mol%) reveals lower detection limit (0.06 ppm) than that of pure SnO 2 sample (1.10 ppm). The superior Cl 2 sensing performance is closely related to the effects of the high-energy facets and the formation of energy barrier between ZnO and SnO 2. [ABSTRACT FROM AUTHOR]

Synthesis of magnetically separable Cu0.5Zn0.5AlxFe2–xO4 nanoparticles was carried out via a chemical co-precipitation route. The synthesis of Cu0.5Zn0.5AlxFe2–xO4-rGO nano-heterostructures was done by the ultrasonication method. Cu0.5Zn0.5AlxFe2–xO4 nanoparticles were characterized by X-ray diffraction (XRD). XRD analysis confirmed the cubic spinel structure of Cu0.5Zn0.5Fe2O4 nanoparticles and its derivatives (Cu0.5Zn0.5AlxFe2–xO4, where x = 0.00, 0.03, 0.06, 0.09, 0.12, and 0.15). The substitution of Fe3+ ions with Al3+ ions was confirmed by peak shifting in recorded XRD patterns. Further, an energy-dispersive X-ray analysis of all samples showed the variation in Fe3+ and Al3+ contents quantitatively. The characterization of graphite oxide (GO) and reduced graphene oxide (rGO) was carried out via XRD, UV-visible (UV-Vis.), and Raman spectroscopy. The data of all these three techniques confirmed the formation of rGO and GO. The fully characterized rGO was then utilized for making nano-heterostructures with Cu0.5Zn0.5AlxFe2–xO4 nanoparticles. Scanning electron microscopy analysis confirmed the formation of ferrite nanoparticles-rGO nano-heterostructures. The Cu0.5Zn0.5AlxFe2–xO4 nanoparticles and Cu0.5Zn0.5AlxFe2–xO4-rGO nano-heterostructures were subjected to various types of characterizations for their potential applications. Electrochemical impedance spectroscopy revealed that the charge transfer resistance significantly reduced for nano-heterostructures as compared to bare Cu0.5Zn0.5Al0.03Fe1.97O4 nanoparticles. The photocatalytic degradation efficiency of the prepared nanoparticles and their nano-heterostructures with rGO was carried out by monitoring the degradation of typical organic compound methylene blue (MB) using UV-Vis. spectroscopy. It is interesting to note that the photocatalytic activity of Cu0.5Zn0.5AlxFe2–xO4 photocatalyst was significantly increased when Cu0.5Zn0.5Al0.03Fe1.97O4/rGO nanocomposites were used as a catalyst. This is because of rGO as it takes the light generated electron from the conduction band of catalyst immediately and thus inhibits the immediate recombination of e––h+ pairs. Secondly, due to the large surface area of rGO sheets, several MB molecules could be adsorbed on its surface. The adsorbed molecules later on degraded by the photocatalytic reaction. [ABSTRACT FROM AUTHOR]

The development of highly active and stable photocatalysts, an effective way to remediate environment pollution and alleviate energy shortages, remains a challenging issue. In this work, a CdIn2S4/In(OH)3 nanocomposite was deposited in-situ on NiCr-LDH nanosheets by a simple hydrothermal method, and the obtained CdIn2S4/In(OH)3/NiCr-LDH heterostructure photocatalysts with multiple intimate-contact interfaces exhibited better photocatalytic activity. The photocatalytic H2 evolution rate of CdIn2S4/In(OH)3/NiCr-LDH increased to 10.9 and 58.7 times that of the counterparts CdIn2S4 and NiCr-LDH, respectively. Moreover, the photocatalytic removal efficiency of Cr(VI) increased from 6% for NiCr-LDH and 75% for CdIn2S4 to 97% for CdIn2S4/In(OH)3/NiCr-LDH. The enhanced photocatalytic performance was attributed to the formation of multi-interfaces with strong interfacial interactions and staggered band alignments, which offered multiple pathways for carrier migration, thus promoting the separation efficiency of photo-excited electrons and holes. This study demonstrates a facile method to fabricate inexpensive and efficient heterostructure photocatalysts for solving environmental problems.

Zirconium substituted magnesium cobalt ferrite (Zr x Mg 0.2-x Co 0.8-x Fe 2 O 4) nanoparticles and their nano-heterostructures with graphene were synthesized by co-precipitation and ultra-sonication route respectively. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) analysis was done to study the effect of Zr4+ substitution on structural properties, surface morphology, dielectric and current-voltage properties of nanoparticles. The crystallite size of nanoparticles was found in the range of 23–28 nm. XRD pattern analysis confirmed the spinel structure of nanoparticles. Graphene synthesized by modified Hummer's method was utilized as substrate to prepare the heterostructures with ferrite particles. Dispersion of nanoparticles on the surface of rGO sheets was confirmed by SEM analysis. Enhanced photocatalytic activity of nanoparticles and graphene based nano-heterostructures was observed under visible light irradiation. During the current-voltage measurements, decrease in electrical resistivity of nanoparticles was observed. Dielectric measurements were performed within the frequency range 1 MHz–3 GHz. Electrochemical impedance spectroscopy was done to evaluate the kinetic parameters and charge-transfer resistance (R ct) at electrode interface. Enhanced photocatalytic applications, suggested that Zr x Mg 0.2-x Co 0.8-x Fe 2 O 4 nanoparticles and graphene based nano-heterostructures can be used for degradation of various organic based pollutants in drinking water. [ABSTRACT FROM AUTHOR]

Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe3O4-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe3O4-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r2 relaxivity (166.5 mM−1·s−1 and 99.5 mM−1·s−1 in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T2 contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/gFe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing.

Rare earth Nd 3+ doped Mg 0.8 Ca 0.2 Fe 2 O 4 nanoparticles were prepared via chemical co-precipitation route. XRD confirmed the cubic structure of all compositions and XRD data was used to determine the lattice constant (a), cell volume (V), crystallite size (D) and porosity. Reduced graphene oxide (rGO) prepared via chemical route was utilized to obtain the Mg 0.8 Ca 0.2 Nd x Fe 2-x O 4 -rGO nanocomposite materials. SEM analysis confirmed the well dispersed Mg 0.8 Ca 0.2 Nd x Fe 2-x O 4 nanoparticles among the graphene sheets. The photocatalytic degradation rate of methylene blue was higher in the presence of nanocomposite as compared to the bare nanoparticles under visible light irradiation. The enhanced photocatalytic activity of Mg 0.8 Ca 0.2 Nd x Fe 2-x O 4 -rGO nanocomposite could be related to the decreased charge transfer resistance of composite materials investigated by electrochemical impedance spectroscopic (EIS) analysis. The value of dielectric constant and dielectric loss decreased with the increase in value of Nd 3+ from 0 to 0.12 mol. [ABSTRACT FROM AUTHOR]

Abstract: The one dimensional Zinc Selenide/Zinc Oxide (ZnSe/ZnO) nano‐heterostructures were prepared using solvo/hydrothermal reaction technique with varying concentration of ZnSe. The prepared nano‐heterostructures were characterized with various techniques. X‐ Ray Diffraction (XRD) indicates the formation of cubic ZnSe and hexagonal phase of ZnO. Field Emission Scanning Electron Microscopy (FESEM) depicts the formation of rod shaped ZnO nanostructures decorated with spherical nanoparticles of ZnSe. Field Emission Transmission Electron Microscopy (FETEM) validates the formation ZnO nanorods of size 30–40 nm along with spherical ZnSe (25‐30 nm) nanostructures. The UV‐Visible absorption spectra analysis clearly depicts the extended absorbance in the visible region. Photoluminescence study indicates the sharp band edge emission peak at 390 nm and broad peak at 475 nm. With further increase in ZnSe concentration, the intensity of band edge emission peak decreases due to the vacancy defects. The photocatalytic performance of prepared ZnSe/ZnO nano‐heterostructure was evaluated by studying the hydrogen (H2) generation via water (H2O) splitting under UV‐Visible light. The ZnSe/ZnO (10:90 weight ratio) shows 491 μmol of H2 generation after 4 hours irradiation. With increase in amount of ZnSe upto 10 mol%, the H2 evolution was also enhanced due to narrowing of the band gap and suppression of recombination rate of charge carriers. [ABSTRACT FROM AUTHOR]

Gas sensors play a vital role on many aspects in our society, and have gained much progress, propelled by the development of nanoscience and nanotechnology. In this regard, metal oxides with heterojunctions have attracted tremendous attention owing to their enhanced gas sensing properties. Herein, belt-tooth shape ZnO/In 2 O 3 nano-heterostructures has been achieved through a chemical vapor deposition process. The gas sensor fabricated from the as-prepared nano-heterostructures exhibits superior sensing performances for C 2 H 2 gas at low operating temperature (90 °C). Moreover, the Au decorated ZnO/In 2 O 3 nano-heterostructures (Au-ZnO/In 2 O 3 ) exhibit enhanced C 2 H 2 sensing properties such as higher response, less response time, better selectivity and smaller deviation from the ideal value of power exponent. More significantly, the response to C 2 H 2 gas is maintained well in 30 days, indicating good long-term stability. In addition, both the potential-barrier-controlled carrier transport model combining with the surface depletion model and the unique properties of Au are presented to describe the C 2 H 2 gas sensing mechanism of Au-ZnO/In 2 O 3 . This study offers an innovative methodology to design novel gas sensing materials and enhance gas sensing performances. [ABSTRACT FROM AUTHOR]

• Mo 2 C/Co nano-heterostructures were embedded in the N-doped carbon. • The nano-heterostructures synergistically enhance electrochemical performance. • Co-NC@Mo 2 C was used as Li-O 2 batteries (LOBs) cathode catalyst. • The LOBs delivers a high discharge capacity and long cycle life. Lithium-oxygen batteries (LOBs) are becoming the rising stars of a new generation of energy storage devices due to high theoretical energy density. The crucial factor of its high performance and stability is developing efficient cathode electro-catalysts. In this work, the Zn 3 [Co (CN) 6 ] 2 Prussian Blue analog (Zn-CoPBA) was used as the precursor, then ammonium molybdate tetrahydrate was incorporated by hydrothermal treatment, and finally Mo 2 C-modified Co-NC was prepared by one-step pyrolysis. The mesoporous hetero-interfaces of N-doped carbon matrix embedded by Mo 2 C/Co nano-heterostructures facilitate the transport of substances, provide more catalytic active sites and storage space for the discharge product Li 2 O 2 due to the characteristic electronic structure and catalytic properties of Mo 2 C with d-orbital state distribution near the noble metal-like Fermi level. The composite Co-NC@Mo 2 C was used for LOBs cathode catalyst, it presents wonderful charge-discharge specific capacities (21,930 mA h g −1), stable cycling performance. In this work, Zn 3 [Co (CN) 6 ] 2 Prussian Blue analog (Zn-CoPBA) was used as the precursor, then ammonium molybdate tetrahydrate was incorporated by hydrothermal treatment, and finally Mo 2 C-modified Co-NC was prepared by one-step pyrolysis. The mesoporous hetero-interfaces of N-doped carbon matrix embedded by Mo 2 C/Co nano-heterostructures facilitate the transport of substances, provide more catalytic active sites and storage space for the discharge product Li 2 O 2. The composite Co-NC@Mo 2 C was used for LOBs cathode catalyst, it presents wonderful charge-discharge specific capacities (21,930 mA h g −1), stable cycling performance (182 cycles). [Display omitted] [ABSTRACT FROM AUTHOR]

Magnetic Co x Zn 1− x Fe 2 O 4 nanoparticles and Co x Zn 1− x Fe 2 O 4 -graphene nano-heterostructures were prepared by chemical co-precipitation route and ultra-sonication method respectively. The characterization of Co x Zn 1− x Fe 2 O 4 nanoparticles was carried out by thermo-gravimetric analysis (TGA), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy, vibrating sample magnetometry (VSM). TGA predicted the phase formation temperature around 850 °C. XRD and FTIR confirmed the single phase cubic structure. Crystallite size as calculated by Scherrer׳s formula was found 50–70 nm; however the nanoparticles size determined by TEM was found 35–75 nm. VSM confirmed the ferromagnetic nature of both ZnFe 2 O 4 and Co 0.3 Zn 0.7 Fe 2 O 4 nanoparticles. The reduced graphene oxide (rGO) prepared by modified Hummer׳s method was characterized by UV–visible (UV–vis) spectroscopy and XRD. As prepared rGO was utilized for preparation of Co x Zn 1− x Fe 2 O 4 -rGO nano-heterostructures. SEM confirmed the well dispersed Co x Zn 1− x Fe 2 O 4 nanoparticles among rGO sheets. Electrochemical impedance spectroscopy (EIS) studies of Co x Zn 1− x Fe 2 O 4 nanoparticles and their nano-heterostructures with rGO showed that Co x Zn 1− x Fe 2 O 4 nanoparticles exhibit the high charge transfer resistance as compared to nano-heterostructures. The photocatalytic efficiency of Co x Zn 1− x Fe 2 O 4 nanoparticles and their nanocomposites with rGO was evaluated using methylene blue as model organic compound in the presence of visible light. The Co x Zn 1− x Fe 2 O 4 -rGO nano-heterostructures showed more efficiency as compared to Co x Zn 1− x Fe 2 O 4 nanoparticles. The ferrite nanoparticles and their nano-heterostructures with rGO could be separated and recycled by conventional magnetic bars easily. [ABSTRACT FROM AUTHOR]

A major issue with Li-O 2 batteries is their slow oxygen reduction and evolution kinetics, necessitating catalysts with high catalytic activity to improve reaction kinetics and cycle stability. Herein, a nano-heterostructured catalyst composed of Co 3 O 4 and Fe 2 O 3 (Co 3 O 4 /Fe 2 O 3 ) with a porous rod morphology is achieved through an interfacial engineering strategy by constructing Fe 2 O 3 on the Co 3 O 4 surface, which can function as a high-performance cathode in order to efficiently encourage the oxygen reduction and evolution while also reduce the battery polarization during charging and discharging. The density functional theory (DFT) calculations show the differences in charge density at the interface of nano-heterostructures, demonstrating the occurrence of an electron transfer process in the interface region of Co 3 O 4 and Fe 2 O 3 , implying a strong electronic coupling transfer, and in turn changing the electronic structure of the Co 3 O 4 . This significantly reduces the adsorption energy of LiO 2 intermediates, thereby effectively lowering the overpotential. The resultant Li-O 2 battery has larger discharge specific capacity, lower overpotential for the efficient oxygen evolution/reduction, as well as good cycling stability of 280 cycles. This work demonstrates an effective method to fabricate the nano-heterostrucutred materials with enhanced catalytic efficiency for advanced energy applications., (© 2022 Wiley-VCH GmbH.)

Harnessing solar energy for the production of clean hydrogen by photo­electrochemical water splitting represents a very attractive, but challenging approach for sustainable energy generation. In this regard, the fabrication of Fe2O3-TiO2 photoanodes is reported, showing attractive performances [≈2.0 mA cm−2 at 1.23 V vs. the reversible hydrogen electrode in 1 M NaOH] under simulated one-sun illumination. This goal, corresponding to a tenfold photoactivity enhancement with respect to bare Fe2O3, is achieved by atomic layer deposition of TiO2 over hematite (α-Fe2O3) nanostructures fabricated by plasma enhanced-chemical vapor deposition and final annealing at 650 °C. The adopted approach enables an intimate Fe2O3-TiO2 coupling, resulting in an electronic interplay at the Fe2O3/TiO2 interface. The reasons for the photocurrent enhancement determined by TiO2 overlayers with increasing thickness are unraveled by a detailed chemico-physical investigation, as well as by the study of photo­generated charge carrier dynamics. Transient absorption spectroscopy shows that the increased photoelectrochemical response of heterostructured photoanodes compared to bare hematite is due to an enhanced separation of photogenerated charge carriers and more favorable hole dynamics for water oxidation. The stable responses obtained even in simulated seawater provides a feasible route in view of the eventual large-scale generation of renewable energy. [ABSTRACT FROM AUTHOR]

• Co 3 O 4 /Co nano-heterostructures embedded in the N-doped graphitized carbon matrix was prepared. • The Co 3 O 4 /Co nano-heterostructure interface and N-doped porous carbon matrix enhance the electrochemical performance synergetically. • The catalyst-based battery delivers a high discharge capacity and long cycle life. Rational design and synthesis of high-performance bifunctional oxygen electrocatalysts with increased effective active sites and facilitated mass/electron transfer are in demand for the lithium-oxygen batteries (LOBs) to overcome the sluggish oxygen reduction/evolution kinetics. Herein, a simple yet effective strategy is proposed by annealing the Prussian blue analog (PBA) precursor under altered calcination conditions to achieve the efficient nano-heterojunction catalysts with optimized active sites. As a result, the obtained porous Co 3 O 4 /Co nano-heterostructures embedded in N-doped graphitized carbon matrix (Co 3 O 4 /Co@NC) exhibit outstanding electrochemical performance with a high specific capacity of 22,156 mA h g−1 at the current density of 100 mA g−1 and excellent stability, obviously superior to the LOBs based on the other single-component catalysts. Systematic investigations suggest that the enhanced electrochemical performance is ascribed to the Co 3 O 4 /Co nano-heterostructure interface and the N-doped porous carbon matrix. This study presents a simple and effective approach for boosting the PBA-derived catalysts with efficient reactivity for various catalytic applications. [Display omitted] [ABSTRACT FROM AUTHOR]

TiO2/NaYF4:Yb3+,Er3+ nano-heterostructures are prepared in situ on the TiO2 photoanode of dye-sensitized solar cells (DSCs). Transmission electron microscopy (TEM) and high-resolution (HR)-TEM confirm the formation of TiO2/NaYF4:Yb3+,Er3+ nano-heterostructures. The up-converted fluorescence spectrum of the photoanode containing the nano-heterostructure confirms electron injection from NaYF4:Yb3+,Er3+ to the condution band (CB) of TiO2. When using a photoanode containing the nano-heterostructure in a DSC, the overall efficiency ( η) of the device is 17% higher than that of a device without the up-conversion nanoparticles (UCNPs) and 13% higher than that of a device containing mixed TiO2 and UCNPs. Nano-heterostructures of TiO2/NaYF4:Yb3+,Tm3+ and TiO2/NaYF4:Yb3+,Ho3+ can also be prepared in situ on TiO2 photoanodes. The overall efficiency of the device containing TiO2/NaYF4:Yb3+,Ho3+ nano-heterostructures is 15% higher than the control device without UCNPs. When nano-heterostructures of TiO2/NaYF4:Yb3+,Tm3+ are used, the open-circuit voltage ( Voc) and the short-circuit current density ( Jsc) are all slightly decreased. The effect of the different UCNPs results from the different energy levels of Er3+, Tm3+, and Ho3+. These results demonstrate that utilizing the UCNPs with the apporpriate energy levels can lead to effective electron injection from the UCNPs to the CB of TiO2, effectively improving the photocurrent and overall efficiency of DSCs while using NIR light. [ABSTRACT FROM AUTHOR]

Nano-heterostructures have attracted great attention due to their extraordinary properties beyond those of their single-component counterparts. This review focuses on a specific type of hybrid structures: core-shell structures. In particular, we present and discuss the recent wet-chemical synthesis approaches for semiconductor and metallic core-shell nanostructures, and their relevant properties and potential applications in photovoltaics and catalysis, respectively. [ABSTRACT FROM AUTHOR]

Zn2SnO4/ZnO wire-sheet shape hetero-nanostructures (Zn2SnO4/ZnO HNS) networks gas sensors have been fabricated on Cr comb-shaped interdigitating electrodes with relatively narrower interspace of 1.5µm using thermal evaporation of the mixed powders of ZnO, SnO2 and active carbon with Au catalysts. The self-assembly grown sensors of Zn2SnO4/ZnO HNS networks have excellent gas sensing characteristics to hydrogen concentration ranging from 2 to 1000ppm at operating temperature of 120–300°C. Comparing with Zn2SnO4/ZnO HNS networks sensors, the Pd decorated Zn2SnO4/ZnO HNS (Pd-Zn2SnO4/ZnO HNS) networks sensors exhibit enhanced hydrogen sensing performance such as higher response (74% at 255°C to 1000ppm H2), less response time (15s at 270°C to 1000ppm H2), better selectivity (response to H2, C2H5OH, CH4, C2H2, CO, and C3H8), lower adsorption activation energy (12.72kJ/mol to 1000ppm H2) and smaller deviation from the ideal value of power exponent ß (0.49623 at 255°C). The enhanced sensing properties of the Pd-Zn2SnO4/ZnO HNS can be ascribed to an additional depletion layer at the interface between Pd nanoparticles and Zn2SnO4/ZnO HNS. Both sensors show fine long-term stability during exposure to 2–1000ppm H2 under relatively high operating temperature of 120–300°C in 50 days. [ABSTRACT FROM AUTHOR]

Highlights: [•] String-like ZnO/SnO nanowire/nanosheet nano-heterostructures were synthesized. [•] The microstructures of the nano-heterostructures were studied in detail. [•] Blue shift of the band related emission of ZnO from the nanostructures was observed. [Copyright &y& Elsevier]

Abstract: The Ag/Tl2Ba2Ca2Cu3O10/CdSe heterostructure was fabricated at room temperature by soft electrochemical processing technique for the first time. The formation of the heterostructure with non-diffusive interfaces was confirmed by X-ray diffraction. The crystallite sizes determined for Tl-2223 and CdSe films were 33nm and 25nm, respectively. The Tl2Ba2Ca2Cu3O10 film electrodeposited onto Ag-substrate has shown the superconducting transition temperature T c at 116.5K and J c =2.1×103 A/cm2. These values were found to improve after the deposition of CdSe onto Ag/Tl-2223 films. The effect of red He–Ne laser irradiation on the superconducting properties of heterostructure are studied and discussed at length in this paper. [Copyright &y& Elsevier]

The coupling of TiO 2 and SrTiO 3 through elaborate bandgap engineering can provide synergies for highly efficient photocatalysts. To further improve the separation between photogenerated electrons and holes, a nano-heterostructured combination of semicrystalline SrTiO 3 (S-SrTiO 3 ) and anatase TiO 2 nanoparticles is designed, and an optimized interface is achieved between uniformly grown S-SrTiO 3 and metal organic framework (MOF)-derived anatase TiO 2 through a controlled hydrothermal process. Besides tuning of the bandgap and broadening of the absorption spectral range, S-SrTiO 3 particles alleviate charge carrier recombination benefiting from the coupling of the semicrystalline SrTiO 3 around the interface. Additionally, highly dispersed S-SrTiO 3 on TiO 2 provides a good spatial distribution of active sites and the abundant carbon remained from MOF may reduce charge transport resistance. Moreover, the rapid transfer within the nano-heterostructure promotes the separation of the photogenerated charge carriers. With the above predominant architecture, when used as a photocatalyst, the as-synthesized S-SrTiO 3 /TiO 2 heterostructure exhibits exceptionally high photocatalytic performance of 13 005 µmol h -1 g -1 for H 2 production, exceeding most oxide-based photocatalysts reported. This study might provide mechanistic insights into a new perspective for the design and preparation of photocatalysts with novel structure and enhanced catalysis activity., (© 2022 Wiley-VCH GmbH.)

The development of highly active and stable photocatalysts, an effective way to remediate environment pollution and alleviate energy shortages, remains a challenging issue. In this work, a CdIn2S4/In(OH)3 nanocomposite was deposited in-situ on NiCr-LDH nanosheets by a simple hydrothermal method, and the obtained CdIn2S4/In(OH)3/NiCr-LDH heterostructure photocatalysts with multiple intimate-contact interfaces exhibited better photocatalytic activity. The photocatalytic H2 evolution rate of CdIn2S4/In(OH)3/NiCr-LDH increased to 10.9 and 58.7 times that of the counterparts CdIn2S4 and NiCr-LDH, respectively. Moreover, the photocatalytic removal efficiency of Cr(VI) increased from 6% for NiCr-LDH and 75% for CdIn2S4 to 97% for CdIn2S4/In(OH)3/NiCr-LDH. The enhanced photocatalytic performance was attributed to the formation of multi-interfaces with strong interfacial interactions and staggered band alignments, which offered multiple pathways for carrier migration, thus promoting the separation efficiency of photo-excited electrons and holes. This study demonstrates a facile method to fabricate inexpensive and efficient heterostructure photocatalysts for solving environmental problems. [ABSTRACT FROM AUTHOR]

Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe3O4-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe3O4-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r2 relaxivity (166.5 mM−1·s−1 and 99.5 mM−1·s−1 in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T2 contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/gFe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing. [ABSTRACT FROM AUTHOR]

The shortcoming of Fe‐based materials, their poor electron transfer efficiency, restricts their electrochemical performance severely. An electric field (E) is induced by an Fe7S8/α‐FeOOH nano‐heterostructure (SACF) via two simple immersion steps at room temperature. The charge transfer from α‐FeOOH to Fe7S8 spontaneously establishes an intrinsic electric field at the Fe7S8/α‐FeOOH nano‐heterostructure boundary. Additionally, the relationship between structure and property is investigated by structural characterization and density functional theory calculations that are used to explain the electron transfer mechanism and good wettability in KOH electrolyte. The results indicate that the electric field accelerates the electron transfer rate during charge/discharge process, provides the most of active materials (both Fe7S8 and α‐FeOOH) and facilitates the contact of active material with electrolyte. When used as the supercapacitor negative electrode, the SACF delivers superior specific capacity of 520.27 F g−1 at 1 A g−1 current density, 2.5 times that of the ACF (α‐FeOOH nanosheet array), and shows excellent cycle life and rate capacity. This work introduces the consideration of electric field into fabricating an effective supercapacitor negative electrode, and helps to understand the function mechanism of nano‐heterojunction when designed in electrode materials. [ABSTRACT FROM AUTHOR]

Engineered atomic dislocations have been used to create a novel, Sb 2 Te 3 nanoplate-like architecture that exhibits a unique antisymmetric chirality. High-resolution transmission electron microscopy (HRTEM) coupled with atomic force microscopy and X-ray photoelectron spectroscopy reveals the architectures to be extremely well ordered with little residual strain. Surface modification of these topologically complex macrostructures (≈3 µm) has been achieved by direct growth of metallic Ag nanoparticles onto the edge sites of the Sb 2 Te 3 . Again, HRTEM shows this nanoparticle decoration to be atomically sharp at the boundaries and regularly spaced along the selvedge of the nanostructure. Transport experiments of densified films of these assemblies exhibit marked increases in carrier density after nanoengineering, yielding 3.5 × 10 4 S m -1 in electrical conductivity. An increased Seebeck coefficient by 20% in parallel with electrical conductivity is also observed. This gives a thermoelectric power factor of 371 µW m -1 K -2 , which is the highest value for a flexible, freestanding film to date. These results suggest an entirely new direction in the search for wearable power harvesters based on topologically complex, low-dimensional nanoassemblies., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)