Hetero Nanostructures Research Articles

In situ self-heterogenization of Cu2S/CuS nanostructures with modulated d band centers for promoting photocatalytic degradation and hydrogen evolution performances

Photocatalytic technology is a promising remedy for energy crises and environmental pollution, but it is still challenging to develop a stable, low-cost, and active photocatalyst for both environmental protection and clean energy production. Herein, a controlled synthesis of stable Cu2S/CuS hetero-nanostructures (HNCs) is achieved by controlling the temperature and time in the hot-injection process, where the Cu2S primary units are grown on certain facets of CuS nanocrystals through an ‘in situ self-heterogenization’ route. It thus creates abundant Cu2S|CuS hetero-interfaces as charge transfer channels to efficaciously increase the quantity of valid active sites and promote the separation of photo-induced carriers. The Cu2S/CuS HNCs achieved a high kinetic constant of 31.7 × 10−3 min−1 for photocatalytic pollutant elimination and exhibited an impressive rate of 1293 μmol h−1 g−1 for photocatalytic hydrogen evolution. Additionally, density functional theory (DFT) calculations indicate that the d band centers of active Cu sites are effectively modulated to reach better positions after building hetero-interfaces, which consequently optimizes the adsorption/desorption of the guest reactants/intermediates on critical active Cu centers following the Sabatier Principle. This can effectively promote the decomposition efficiency of dye molecules and water splitting kinetics for highly improving photocatalytic activities in both photo-degradation for pollutant removal and photo-splitting water for hydrogen generation.

Surface Defect-Driven Chemical Transformation of MoSe2 Nanosheets

The chemistry of atomically thin two-dimensional layered transition metal dichalcogenides (TMDs) largely depends upon the presence of defect sites in their structures. Here, we demonstrate the role of defects of MoSe2 nanosheets (NSs) in two different transformative reactions for the synthesis of MoSe2–CdS nano-heterostructures (NHSs) and CdSe quantum dots (QDs). MoSe2–CdS NHSs are synthesized via passivating the defects of MoSe2 using thiol moieties, followed by the growth of CdS over the surface of MoSe2 NSs. Furthermore, in the absence of thiols, we observe that defects in MoSe2 NSs significantly accelerate the cation-exchange process upon direct exposure to the cadmium (Cd) precursor, resulting in the formation of CdSe QDs through cation displacement reaction (CDR). We have probed the transformation of MoSe2 NSs into CdSe QDs through Raman and optical spectroscopic measurements. Furthermore, theoretical calculations under the framework of density functional theory (DFT) suggest that CDR is feasible on the surface of defect-rich NSs, which becomes unfavorable in the case of defect-free or thiol-passivated MoSe2 NSs. These results provide new insights into understanding the multifaceted role of defects of TMDs in different transformative reactions.

Region-Controlled Framework Interface Mediated Anion Exchange Chemical Transformation to Designed Metal Phosphosulfide Heteronanostructures.

Postsynthetic chemical transformation provides a powerful platform for creating heteronanostructures (HNs) with well-defined materials and interfaces that generate synergy or enhancement. However, it remains a synthetic bottleneck for the precise construction of HNs with increased degrees of complexity and more elaborate functions in a predictable manner. Herein, we define a general transformative protocol for metal phosphosulfide HNs based on tunable hexagonal Cu1.81S frameworks with corner-, edge- and face-controlled growth of Co2P domains. The region-controlled Cu1.81S-Co2P framework interfaces can serve as "kinetic barriers" in mediating the direction and rate between P and S anion exchange reactions, thus leading to a family of morphology and phase designed Cu3P1-xSx-Co2P HNs with hollow (branched, dotted and crown), porous and core-shell architectures. This study reveals the internal transformation mechanism between metal sulfide and phosphide nanocrystals, and opens up a new way for the rational synthesis of metastable HNs that are otherwise inaccessible.

Defect Passivation Results in the Stability of Cesium Lead Halide Perovskite Nanocrystals

Nanoheterostructures (NHSs) based on lead halide perovskites (LHPs) and chalcogenide quantum dots have proved to be promising candidates for photovoltaic device applications. However, understanding the defect chemistry at the interfaces of LHPs and chalcogenides is essential to stabilize them and further tune their optoelectronic properties. Here, we demonstrate a route for designing CsPbBr3–PbSe NHSs and other derivatives of LHP-based NHSs using defect-rich MoSe2 nanosheets (NSs) and study the effect of the size of PbSe NPs on their optical properties. In this synthesis route, PbSe nanoparticles (NPs) are formed at an early stage of the reaction through a unique cation displacement reaction, over which CsPbBr3 nanocrystals (NCs) are epitaxially grown. Using this methodology, a nearly 3-fold enhancement in photoluminescence (PL) is achieved, whereas other selenium precursors, which form larger PbSe NPs, result in negligible PL enhancement with respect to the pure CsPbBr3 NCs. Detailed density functional theory (DFT) calculations suggest that the PbSe NPs are responsible for passivating the surface defects that consequently enhance the PL intensity. However, in the case of larger PbSe NPs, the associated valence and conduction bands lie within the band-gap region of CsPbBr3, creating a type-I heterostructure between the two materials, thereby affecting the luminescence properties. Strong passivation of surface defects in CsPbBr3–PbSe NHSs is also evidenced from low-temperature PL studies. Furthermore, the resulting CsPbBr3–PbSe NHSs demonstrate enhanced stability in the presence of water and do not degrade under ambient conditions for several months.

Investigate the suitability of g-C3N4 nanosheets ornamented with BiOI nanoflowers for photocatalytic dye degradation and PEC water splitting

The two-step thermal polymerization and solvothermal approach is used to construct nano heterostructures of FCN and BiOI (bismuth oxeye iodide), both of which are Nobel metal-free materials. This work reports the effect nano-heterostructure on the micro-structural, light absorption capability, PEC properties and pollutant degradation efficiency of the synthesised heterostructures. The addition to that formation of FCN/BiOI nano-heterostructure enhances the solar light absorption. The FCN/BiOI nano heterostructure shows 10 times higher photocurrent density than the BCN nanostructure and 3.8 time higher that FCN. The FCN/BiOI has a high induced photo-current density (20.17 mA/cm2) and H2 evolution rate (3762 μmol h−1 cm−2) under solar light illumination (λ ≥ 420 nm) in comparison with the other. Furthermore, the photocatalytic performance of this material for the breakdown of methyl red dyes was much greater. Under solar light irradiation, the azo dyes were degraded in 90 min. The FCN/BiOI nano-heterostructure has a higher dye degradation efficiency of 97.91%. The rapid transport of photo-induced electrons in the FCN/BiOI nanocomposite is responsible for the improvement in PEC and PC performances. These impressive findings suggest that this nanocomposite might be used to facilitate the PEC water splitting and the PC degradation of MR in the presence of light. The current research provides insight on how to best tailor composition and structure for efficient FCN photo-electrocatalysis water splitting and Methyl red dye degradation.

Charge Carrier Dynamics of CsPbBr3/g-C3N4 Nanoheterostructures in Visible-Light-Driven CO2-to-CO Conversion

The photon energy-dependent selectivity of photocatalytic CO2-to-CO conversion by CsPbBr3 nanocrystals (NCs) and CsPbBr3/g-C3N4 nanoheterostructures (NHSs) was demonstrated for the first time. The surficial capping ligands of CsPbBr3 NCs would adsorb CO2, resulting in the carboxyl intermediate to process the CO2-to-CO conversion via carbene pathways. The type-II energy band structure at the heterojunction of CsPbBr3/g-C3N4 NHSs would separate the charge carriers, promoting the efficiency in photocatalytic CO2-to-CO conversion. The electron consumption rate of CO2-to-CO conversion for CsPbBr3/g-C3N4 NHSs was found to intensively depend on the rate constant of interfacial hole transfer from CsPbBr3 to g-C3N4. An in situ transient absorption spectroscopy investigation revealed that the half-life time of photoexcited electrons in optimized CsPbBr3/g-C3N4 NHS was extended two times more than that in the CsPbBr3 NCs, resulting in the higher probability of charge carriers to carry out the CO2-to-CO conversion. The current work presents important and novel insights of semiconductor NHSs for solar energy-driven CO2 conversion.

Efficiency enhancement of photocatalytic activity under UV and visible light irradiation using ZnO/Fe3O4 heteronanostructures

ZnO/Fe3O4 heteronanostructures (HNSs) have attracted great attention due to their possibility of removing organic pollutants in aqueous solutions, then detaching from aqueous solutions by magnetic fields. However, there is a lack of research on their photocatalytic performance under visible light irradiation and the mechanism for the degradation process is still arguable. We present here the enhancement in the photocatalytic activity of ZnO/Fe3O4 HNSs, synthesized by a facile hydrothermal technique, under both Ultraviolet (UV) and visible light irradiation. Particularly, the methylene blue (MB) degradation efficiency exhibited a great enhancement of up to 99.7% and 79.7% for HNSs with different ZnO:Fe3O4 mole ratios of 16:1 and 8:1 under UV and visible light, respectively. It could be explained by the transfer of electrons (i) from the conduction band (CB) of ZnO to that of Fe3O4 or/and (ii) from the CB of Fe3O4 to new defect states (e.g., Fe2+/Fe3+ levels) below the CB of ZnO. Additionally, ZnO/Fe3O4 HNSs show great stability in their photocatalytic activities when remained 95.1% and 92.1% after 5-reused cycles under UV and visible light irradiation, respectively. Therefore, the fabricated ZnO/Fe3O4 HNSs show great potential for enhancing the MB degradation efficiency under both UV and visible light.

Flexible PAN-Bi2O2CO3–BiOI heterojunction nanofiber and the photocatalytic degradation property

In this paper, one-dimensional PAN-Bi2O2CO3–BiOI photocatalytic nanofibers were prepared using flexible PAN nanofibers as carriers. Bi2O2CO3 was first grown on the surface of PAN nanofibers, and then BiOI was loaded on Bi2O2CO3 by ion exchange method. The characterization results showed that PAN-Bi2O2CO3–BiOI nanofibers have a diameter of about 210 nm and regular fiber morphology. The results of UV–Vis diffuse reflectance spectroscopy, XRD and XPS showed that Bi2O2CO3–BiOI composed of granular semiconductor nano heterostructures with high specific surface area were uniformly loaded on the surface of PAN fiber. The photocatalytic degradation experiment of the material showed high visible light photocatalytic activity. The preparation of Bi2O2CO3–BiOI heterojunction improved the photoelectron hole separation efficiency of BiOI under visible light. PAN-Bi2O2CO3–BiOI fibers showed high photocatalytic degradation efficiency for rhodamine B. The degradation efficiency was more than 95% within 120 min irradiation. Free radical trapping experiments showed photocatalysts mainly produced O2−,·OH and h+, which played a major role in photocatalysis.

Interfacial engineering of Ag nanoparticle-decorated polypyrrole@Co(OH)2 hetero-nanostructures with enhanced energy storage for hybrid supercapacitors

Battery-type electrode materials (BTEMs) still suffer from unsatisfactory actual specific capacities and cycling stability, which impede their applications in hybrid supercapacitors (HSCs). Herein, we report an interfacial engineering strategy to improve the energy storage performance of Co(OH)2-based BTEMs by constructing the polypyrrole (PPy)@Co(OH)2 @Ag hetero-nanostructures (HNs). In such HNs, Co(OH)2 nanosheets are initially grown onto PPy nanowires on Ni foam, which offer rich electroactive sites, efficient charge transport, and good mechanical stability. More importantly, density functional theory (DFT) calculation results indicate that the subsequent decoration of Ag NPs on Co(OH)2 nanosheets provides an enhanced electrical conductivity as well as a reduced surface adsorption energy of OH- at Co(OH)2 nanosheets compared to the PPy@Co(OH)2 HNs without the decoration of Ag NPs. Consequently, the prepared PPy@Co(OH)2 @Ag electrode material demonstrates a specific capacity of up to 277 mA h g−1 at 2 A g−1, 72 % capacity retention at 20 A g−1 together with a 92 % capacity retention over 5000 cycles at 10 A g−1. Furthermore, a HSC device using the PPy@Co(OH)2 @Ag as positive electrode has been fabricated to achieve an energy density of 54.4 W h kg−1 at 800 W kg−1. This work provides a new insight into the structural design of BTEMs for their applications in HSCs.

Enhanced photo-electrocatalytic performance of the nano heterostructures based on Pr3+ modified g-C3N4 and BiOI

Due to their superior optoelectronic characteristics and affordable cost, doped few-layered g-C3N4 (FCN) semiconductor nanostructures are attractive for photocatalytic and photoelectrochemical (PEC) water splitting applications. Nano heterostructures composed of Praseodymium (Pr)-doped few-layered graphitic carbon nitrides (FCN) and bismuth oxy iodide (BiOI) are manufactured using thermal condensation and hydrothermal technique in two steps. The inclusion of Pr dopant not only modifies the FCN by increasing its porosity and specific surface area, but also improves electron-hole separation and charge transfer. The metal-free nano heterostructure (Pr: FCN/BiOI) that was created exhibits a strong electron-hole separation. The observed rapid charge transit in a heterojunction results in a low rate of charge recombination. Thus, the produced metal-free nano heterostructure overcomes the barrier of FCN's high photo-charge carrier recombination rate. This study investigates the influence of Pr-doping on the structural, optical, electrical conductivity, and PEC characteristics of produced heterostructures. The addition of Pr dopant to FCN increases its ability to absorb solar light. The photocurrent density of the 1.5 wt percent Pr: FCN/BiOI nano heterostructure is 16.8 times greater than that of the 1.5 wt percent Pr: FCN nanostructure. In comparison to the other Pr-doping doses, it exhibits a high hydrogen evolution reaction (HER) photocurrent density (18.21 mA/cm2) and hydrogen evolution rate (3400 mol h−1 cm−2) under solar light irradiation (420 nm). The current work gives significant insight into the optimization of composition and structural features for FCN photoelectrocatalysis with excellent performance.

Selective-Epitaxial Hybrid of Tripartite Semiconducting Sulfides for Enhanced Solar-to-Hydrogen Conversion.

The design and synthesis of advanced semiconductors is crucial for the full utilization of solar energy. Herein, colloidal selective-epitaxial hybrid of tripartite semiconducting sulfides CuInS2 Cd(In)SMoS2 heteronanostructures (HNs) via lateral- and vertical-epitaxial growths, followed by cation exchange reactions, are reported. The lateral-epitaxial CuInS2 and Cd(In)S enable effective visible to near-infrared (NIR) solar spectrum absorption, and the vertical-epitaxial ultrathin MoS2 offer sufficient edge sulfur sites for the hydrogen evolution reaction (HER). Furthermore, the integrated structures exhibit unique epitaxial-staggered type II band alignments for continuous charge separation. They achieve the H2 evolution rate up to 8 mmol h-1 g-1 , which is ≈35 times higher than bare CdS and show no deactivation after long-term cycling, representing one of the most efficient and robust noble-metal-free photocatalysts. This design principle and transformation protocol open a new way for creating all-in-one multifunctional catalysts in a predictable manner.

Pt nanoparticles coupled with perylene-based small molecule deposited on Ti3+ self-doped TiO2 nanorods-An inorganic/organic type-II nanoheterostructure for efficient visible-light photoelectrochemical water oxidation.

In the work reported in this article, we have coupled Ti3+-self-doped TiO2 nanorods (NRs) with a newly synthesized tetrathiophene coupled perylene-based molecule (tThTMP) to form type-II inorganic/organic nanoheterostructures (NHs) for visible-light-driven water oxidation. The small organic molecule helps in better utilizing a wide range of the visible light spectrum, facilitates a faster delocalization of the photogenerated carriers at the inorganic/organic heterojunction, and exhibits improved photoelectrochemical performances. We have further decorated the NHs with platinum nanoparticles (NPs). The decoration of the Pt NPs significantly augments the various aspects of photoelectrochemical performances. The Pt NPs decorated NHs photoanode exhibits a photocurrent density of 0.83mA/cm2 at 1.23V vs. RHE (@10mV/s scan rate), a photoconversion efficiency of 0.26%, a substantial cathodic shift in the water oxidation onset potential and flat band potential, impressively reduced charge transfer resistance, improved photocarrier concentration, photovoltage, and stability.

Atomic-scale Fabrication of 1D-2D Nano Hetero-structures within 2D Materials through Automated Tracking and Electron Beam Control

Atomic-scale Fabrication of 1D-2D Nano Hetero-structures within 2D Materials through Automated Tracking and Electron Beam Control

Graphitic carbon nitride embedded Ni3(VO4)2/ZnCr2O4 Z-scheme photocatalyst for efficient degradation of p-chlorophenol and 5-fluorouracil, and genotoxic evaluation in Allium cepa

Visible light photocatalysis using nano heterostructures offers an eco-friendly alternative for the removal of organic molecules. Here, we reported an enhanced photocatalytic activity of g-C3N4/Ni3(VO4)2/ZnCr2O4, a dual Z-scheme nano-heterojunction for the photocatalytic removal of p-chlorophenol (p-CP) and 5-fluorouracil (5-FU). The nano heterojunction was fabricated by a facile co-precipitation method. Initially, the fabricated nanocomposites (NCs) were characterized for Physico-chemical and optoelectronic properties, by XRD, XPS, SEM, TEM, UV–Visible DRS, BET, PL, and EIS. The fabricated g-C3N4/Ni3(VO4)2/ZnCr2O4 has shown excellent photocatalytic activity. The complete mineralization of both p-CP and 5-FU observed after 160 and 200 min of visible light irradiation respectively. The mineralization of p-CP and 5-FU was confirmed by total organic carbon (TOC) estimation and the percentage of removal TOC for p-CP and 5-FU was 99.25% and 98.9% respectively. The stability of the particle was confirmed by six cycles test. The reusable efficiency of the NCs was found to be 99.7% after six consequent cycles. The stability of the NCs was confirmed by XRD and XPS analysis of reused photocatalyst. The scavengers assay and ESR analysis confirmed the major role of •OH radicals in enhanced photocatalytic activity. The degradation pathway of p-CP and 5-FU was determined by GC–MS/MS and the possible toxicity of the intermediate compounds was determined by the ECOSAR program, which shows the non-toxic nature of the end product on green algae, daphnia, and fish. The toxicity of the NCs was tested against Allium cepa which further confirm the non-toxic nature of NCs. The study suggests that fabricated g-C3N4/Ni3(VO4)2/ZnCr2O4 NCs can be utilized for environmental remediation applications.

Polycrystalline CoO−Co9S8 Heterostructure Nanoneedle Arrays as Bifunctional Catalysts for Efficient Overall Water Splitting

AbstractIt is a great challenge to synthesize efficient electrocatalysts for overall water splitting, especially non‐noble metal catalysts. Herein, one‐dimensional polycrystalline nanoneedles composed of CoO−Co9S8 nano heterostructures, in situ grown on carbon fiber paper are prepared for efficient overall water electrolysis. Due to strong electronic coupling, charge densities of Co2+/Co3+ in Co9S8 and Co2+ in CoO are favorably modified at the interface of CoO and Co9S8, resulting in optimized reaction intermediates absorption and greatly enhanced bifunctional HER/OER activities. CoO−Co9S8/CFP delivers a current density of 10 mA cm−2 in alkaline electrolyte at overpotentials of 184 mV and 270 mV for HER and OER, respectively. When used as electrocatalyst for overall water splitting, it needs a low cell potential of 1.66 V to realize water electrolysis at 10 mA cm−2. This work provides a new strategy to tune the electronic structures of transitional metal active sites via constructing nano heterostructures for efficient water electrolysis.

Insight into morphology dependent charge carrier dynamics in ZnSe-CdS nanoheterostructures.

Semiconductor nanoheterostructures (NHSs) are being increasingly used for the photocatalytic conversion of solar energy in which photo-induced charge separation is an essential step and hence it is necessary to understand the effect of various factors such as size, shape, and composition on the charge transfer dynamics. Ultrafast transient absorption spectroscopy is used to investigate the nature and dynamics of photo-induced charge transfer processes in ZnSe-CdS NHSs of different morphologies such as nanospheres (NSs), nanorods (NRs), and nanoplates (NPs). It demonstrates the fast separation of charge carriers and localization of both charges in adjacent semiconductors, resulting in the formation of a charge-separated (CS) state. The lifetime of the charge-separated state follows the order of NSs < NPs < NRs, emphasizing the effect of morphology on the enhancement of photo-induced charge separation and suppression of backward recombination. The separated charge carriers have been utilized in visible light driven hydrogen production and the hydrogen generation activity follows the same order as that for the lifetime of the CS state, underlining the role of charge separation efficiency. Therefore, the variation of the morphology of NHSs plays a significant role in their charge carrier dynamics and hence the photocatalytic hydrogen production activity.

TEMPLATE DIRECTED FORMATION OF METALLIC IN/(0001) SURFACE OF Sb2Te3 2D LAYERED SEMICONDUCTOR SELF-ASSEMBLING NANOSYSTEM

The cleavage surface of Sb 2 Te 3 layered chalcogenide crystal like as other 2D layered ones, such as InSe, In 4 Se 3 , InTe, is provided as a nanoscale embossed template for the formation of arrays of self-assembled In nanostructures due to thermal deposition and subsequent solid state dewetting (SSD) procedure. Sb 2 Te 3 samples were characterised by X –ray diffraction (XRD), X –ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunneling microscopy/spectroscopy (STM/STS). Sb 2 Te 3 has got the anisotropic crystal structure with the presence of van der Waals interlayer interactions. The studied (0001) surfaces were stable with a specific surface relief, which, as in the cases of other layered crystals In 4 Se 3 , InSe, InTe, is due to the crystal structure of the layer package. The shape of single In induced nanostructure and their array’s symmetry are directed by the (0001) surface lattice symmetry. We observed the formation of triangular shaped In nanostructures ordered in hexagonal structured arrays with the well-defined lattice parameter after the SSD. That is, it can be argued that the cleavage (0001) surface of the Sb 2 Te 3 crystal actually works as a spatially distributed ordered set of cells, which act as a guiding factor for the self-organization of nanostructures due to SSD process on the macroscale. The comparative fractal analysis of STM images of the (0001) Sb 2 Te 3 and (0001) InSe surfaces, shows that distribution in size of In nanostructures are almost the same under commensurate experimental conditions. Sb 2 Te 3 energy gap determined from STS spectra of initial surfaces is approaching value of 0.2 eV. An increase in the degree of In coverage is expressed in DOS distribution with appearance of its sufficient value in the range of Sb 2 Te 3 energy gap. Keywords: layered crystal chalcogenides, self-assembled nanostructures, nanostructures’ template directed assembly, hetero nanostructures, solid state dewetting, LEED, STM/STS, XPS.

Recent Advances in Heterostructured Carbon Materials as Anodes for Sodium‐Ion Batteries

Carbon materials have attracted extensive attention as anodes for sodium‐ion batteries (SIBs) because of the abundant resources, low cost, and diverse structure. Due to the different structure configurations, hard carbons, soft carbons, as well as nanocarbons present distinct electrochemical Na‐storage behaviors and properties. The diverse structural and chemical characteristics of carbon materials’ precursors have paved pathways to construct a robust carbon‐based heterostructure with enhanced electrochemical performances. This review comprehensively discusses the fabrication of carbon‐based heterostructures, including hard–hard, hard–soft, and hard–nano heterostructures, with a focus on the formation processes and the benefits of these heterostructures in Na‐ion storage. Furthermore, the key obstacles and potential production of such heterostructures are explored, disclosing future structural design of high‐performance carbon‐based anode materials for SIBs.

Localized surface plasmon-enhanced photoelectrochemical water oxidation by inorganic/organic nano-heterostructure comprising NDI-based D-A-D type small molecule

This research article reports the visible-light-driven photoelectrochemical water oxidation performances of the plasmonic Au-Pd nanoparticle-decorated inorganic/organic nano-heterostructures (NHs)—B-TiO2/NDIEHTh@Au-Pd. The inorganic constituent of the NHs consists of boron-doped TiO2 nanorods (NRs) grown on fluorine-doped tin oxide (FTO) coated glass substrate. The organic part (NDIEHTh) consists of an acceptor naphthalene diimide (NDI)-based donor–acceptor-donor (D-A-D) type small molecule, in which thiophene serves as the donor. Because of the benefits of the localized surface plasmon resonance (LSPR) effect, the Au-Pd binary alloy nanoparticles substantially ameliorate the visible-light-driven photoelectrochemical performances of the B-TiO2/NDIEHTh@Au-Pd NHs photoanode compared to the B-TiO2/NDIEHTh NHs photoanode. The photocurrent densities exhibited by the B-TiO2/NDIEHTh NHs, and B-TiO2/NDIEHTh@Au-Pd NHs photoanodes at 1 V vs Ag/AgCl are 0.68 mA/cm2 and 1.59 mA/cm2, respectively, manifesting 209% and 623% increments in the photocurrent density compared to that shown by B-TiO2 NRs photoanode. Besides, the B-TiO2/NDIEHTh@Au-Pd NHs photoanode offers a significantly cathodically shifted water oxidation potential, reduced charge transfer resistance, better surface injection efficiency, and most importantly, superior photostability compared to the B-TiO2/NDIEHTh NHs photoanode. The enhancement in the different photoelectrochemical performances could be attributed to the various advantages of LSPR, such as enhanced light absorbance, light concentration, hot electron injection, and plasmon-induced resonance energy transfer.

Enhanced photocatalytic hydrogen production activity of Janus Cu1.94S-ZnS spherical nanoheterostructures

Photocatalytic hydrogen evolution is one of the most promising approaches for efficient solar energy conversion. The light-harvesting ability and interfacial structure of heterostructured catalysts regulate the processes of photon injection and transfer, which further determines their photocatalytic performances. Here, we report a Janus Cu1.94S-ZnS nano-heterostructured photocatalyst synthesized using a facile stoichiometrically limited cation exchange reaction. Djurleite Cu1.94S and wurtzite ZnS share the anion skeleton, and the lattice mismatch between immiscible domains is ∼1.7%. Attributing to the high-quality interfacial structure, Janus Cu1.94S-ZnS nanoheterostructures (NHs) show an enhanced photocatalytic hydrogen evolution rate of up to 0.918 mmol h−1 g−1 under full-spectrum irradiation, which is ∼38-fold and 17-fold more than those of sole Cu1.94S and ZnS nanocrystals (NCs), respectively. The results indicate that cation exchange reaction is an efficient approach to construct well-ordered interfaces in hybrid photocatalysts, and it also demonstrates that reducing lattice mismatch and interfacial defects in hybrid photocatalysts is essential for enhancing their solar energy conversion performance.