High-performance Heterojunction Research Articles

Highly efficient adsorption and visible-LEDs-driven photodegradation of tetracycline over novel and green-synthesized p-BiOI/n-Bi2WO6 heterojunctions

Preparing bismuth compounds-based heterojunctions with superior redox capability has emerged as a promising strategy for environmental remediation. Herein, p-BiOI/n-Bi2WO6 heterojunctions were successfully obtained via a novel, facile, and green solvothermal method. The heterojunctions were synthesized using different mass ratios (1:2, 1:1, and 2:1) of BiOI (BI) and Bi2WO6 (BW), with 1:1 as the best ratio, which was decorated with silver nanoparticles (Ag-NPs) and nitrogen-doped graphene (NG) applying green methodologies. The as-prepared BI/BW heterojunctions were characterized by several techniques, and their adsorption capacity and photodegradation activity toward tetracycline (TC) under 19 W visible LEDs illumination were investigated. The capacity of pure BI, BW and BI/BW heterojunctions for adsorbing TC ranged from 14 to 68 mg/g; among the heterojunctions, Ag/1BI/1BW showed the highest TC adsorption capacity, 35 mg/g. Moreover, the photocatalytic tests revealed that the Ag/1BI/1BW exhibited the highest catalytic performance, achieving a TC percentage degradation of 81 % within 120 min. The low nominal power consumption of the LED-based photoreactor (0.0475 kWh) was significantly lower than that reported in the literature for using Xe or Hg lamps. In addition, catalyst dosage, initial TC concentration, and solution pH were investigated, demonstrating that they play important role in TC photodegradation. Scavenger assays determined that the degradation of TC using Ag/1BI/1BW proceeds mainly via superoxide radicals and holes, which agrees with the carrier transfer mechanism postulated for this heterojunction. TOC analysis revealed that the efficiency of Ag/1BI/1BW was 63 %, and reuse tests confirmed its high performance even after three cycles. This research provides new insights into the design of high-performance heterojunctions for water treatment.

Solar Light-Induced Photoelectrochemical H2 Generation Over Hierarchical TiO2 Nanotube Arrays Decorated with CdS Nanoparticles

The process of converting solar energy into chemical energy through photoelectrochemical (PEC) water splitting holds significant promise for hydrogen and oxygen gas production. In the current study, we have demonstrated the feasibility of designing a high-performance heterojunction photoanode in a scalable manner. This photoanode sensitizes visible light active CdS onto hierarchical TiO2 nanotubes (TNT), thereby enhancing H2 generation. To achieve this, we initially employed an electrochemical anodization technique to fabricate vertically aligned self-organized TNT on a titanium (Ti) substrate. Subsequently, we designed a hierarchical structure for TNT by uniformly decorating them with TiO2 nanoparticles (NPs), thus amplifying the available surface area. By employing the sequential ionic layer adsorption and reaction (SILAR) technique, we establish visible light sensitization. The resulting decorated hierarchical TNT photoanode demonstrates an enhanced photocurrent of 2.60 mA cm−2 under AM 1.5 G simulated solar light, surpassing the performance of hierarchical TNT, and most importantly classic CdS/TNT structures by 17-fold, and 1.6-fold, respectively. Moreover, the developed photoanodes achieved photoconversion efficiency with an applied bias (ABPE) of 2.48%. Thus, this work shows that a hierarchical scaffold can be exploited to achieve enhanced activity in photoelectrochemical H2 generation.

Chitosan synergizes with bismuth-based metal-organic frameworks to construct double S-type heterojunctions for enhancing photocatalytic antimicrobial activity

In recent years, photocatalytic technology has been introduced to develop a new kind antimicrobial agents fighting antibiotic abusing and related drug resistance. The efforts have focused on non-precious metal photocatalysts along with green additives. In the present work, a novel bis-S heterojunctions based on the coupling of polysaccharide (CS) and bismuth-based MOF (CAU-17) s synthesized through a two-step method involving amidation reaction under mild conditions. The as prepared photocatalyst literally extended the light response to the near-infrared region. Owing to its double S-type heterostructure, the lifetime of the photocarriers is significantly prolonged and the redox capacity are enhanced. As a result, the as prepared photocatalyst indicated inhibition up to 99.9 % under 20 min of light exposure against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria as well as drug-resistant bacteria (MRSA). The outstanding photocatalytic performance is attributed to the effective charge separation and migration due to the unique double S heterostructure. Such a double S heterostructure was confirmed through transient photocurrent response, electrochemical impedance spectroscopy tests and electron spin resonance measurements. The present work provides a basis for the simple synthesis of high-performance heterojunction photocatalytic inhibitors, which extends the application of CAU-17 in environmental disinfection and wastewater purification.

Polyelectrolyte modified black phosphorus/titania nanosheet heterojunction enhanced photocatalysis: Synergistic enhancement effect of interface affinity and electron transport channel

The instability and high electron-hole recombination have limited the application of black phosphorus (BP) as an excellent photocatalyst. To address these challenges, poly dimethyl diallyl ammonium chloride (PDDA), poly (allylamine hydrochloride) (PAH), and polyethyleneimine (PEI) are introduced to the functionalization of BP (F-BP), which can not only enhance its stability, but also boost the carrier transfer. Furthermore, a high-performance heterojunction photocatalyst is fabricated using F-BP and titania nanosheets (TNs) via a layer-by-layer self-assembly approach. The experimental outcomes unequivocally indicate that F-BP exhibits fast charge migration compared to BP. The density functional theory (DFT), in situ Kelvin-probe force microscopy (KPFM) and other advanced characterization techniques collectively unfold that PDDA modified BP can notably boost separation and propagation of charges, along with an enhanced carrier abundance. In summary, this novel strategy of using polyelectrolytes to enhance the electron transfer and the stability of BP permits immense potential in building next-generation BP-based high efficiency photocatalysts.

Integrating interface engineering and plasmonic effect to boost photoresponse performance of ZnO:Ga/GaN heterojunction self-powered UV photodetectors

The ability to function without an external power supply makes photodetectors highly promising for use in a new generation of wirelessly and independently operated ultraviolet (UV) photodetection and imaging systems. However, self-powered photodetectors' high dark current, inadequate light harvesting, and poor carrier separation prevent them from attaining high-efficiency UV photodetection and imaging. Herein, a high-performance heterojunction UV photodetector consisting of a single Ga-doped ZnO microwire enshrouded by Ag nanowires (AgNWs@ZnO:Ga MW), a MgO electron blocking layer, and a p-type GaN wafer was proposed. Taking full advantage of the interface engineering and plasmonic effects, the AgNWs@ZnO:Ga MW/MgO/GaN photodetector achieves high photodetection performance with an excellent responsivity of 262 mA/W, a remarkable external quantum efficiency of 92.37%, and a high detectivity of 1.966 × 1012 Jones under 370 nm illumination with power density of 0.22 mW/cm2. Furthermore, it also demonstrates ultrafast pulsed photoresponse speed with a rise/fall time of 3.64 μs/252 μs. An UV imaging system is designed based on the AgNWs@ZnO:Ga MW/MgO/GaN self-powered photodetector, allowing for high-quality, accurate, and distinct object imaging. This work combines interface engineering and plasmonic effects for achieving high-performance UV photodetection, which provides a strategic approach to the development of highly efficient optoelectronic devices.

Rational Design of Three Dimensional Hollow Heterojunctions for Efficient Photocatalytic Hydrogen Evolution Applications.

The efficiency of photocatalytic hydrogen evolution is currently limited by poor light adsorption, rapid recombination of photogenerated carriers, and ineffective surface reaction rate. Although heterojunctions with innovative morphologies and structures can strengthen built-in electric fields and maximize the separation of photogenerated charges. However, how to rational design of novel multidimensional structures to simultaneously improve the above three bottleneck problems is still a research imperative. Herein, a unique Cu2O─S@graphene oxide (GO)@Zn0.67Cd0.33S Three dimensional (3D) hollow heterostructure is designed and synthesized, which greatly extends the carrier lifetime and effectively promotes the separation of photogenerated charges. The H2 production rate reached 48.5mmolg-1h-1 under visible light after loading Ni2+ on the heterojunction surface, which is 97 times higher than that of pure Zn0.67Cd0.33S nanospheres. Furthermore, the H2 production rate can reach 77.3mmolg-1h-1 without cooling, verifying the effectiveness of the photothermal effect. Meanwhile, in situ characterization and density flooding theory calculations reveal the efficient charge transfer at the p-n 3D hollow heterojunction interface. This study not only reveals the detailed mechanism of photocatalytic hydrogen evolution in depth but also rationalizes the construction of superior 3D hollow heterojunctions, thus providing a universal strategy for the materials-by-design of high-performance heterojunctions.

A nanoflower-like GaSe/β-Ga2O3 based heterostructure for highly efficient self-powered broadband photodetectors

The combination of GaSe nanoflowers with β-Ga2O3 results in a high-performance heterojunction photodetector with self-powered operation and outstanding responsivity from deep UV to visible wavelengths.

A g-C3N4/rGO/Cs3Bi2Br9 mediated Z-scheme heterojunction for enhanced photocatalytic CO2 reduction.

Photocatalytic CO2 reduction plays a crucial role in advancing solar fuels, and enhancing the efficiency of the chosen photocatalysts is essential for sustainable energy production. This study demonstrates advancements in the performance of g-C3N4 as a photocatalyst achieved through surface modifications such as exfoliation to increase surface area and surface oxidation for improved charge separation. We also introduce reduced graphene oxide (rGO) in various ratios to both bulk and exfoliated g-C3N4, which effectively mitigates charge recombination and establishes an optimal ratio for enhanced efficiency. g-C3N4/rGO serves to fabricate a hybrid organic/inorganic heterojunction with Cs3Bi2Br9, resulting in a g-C3N4/rGO/Cs3Bi2Br9 composite. This leads to a remarkable increase in photocatalytic conversion of CO2 and H2O to CO, H2 and CH4 at rates of 54.3 (±2.0) μmole- g-1 h-1, surpassing that of pure Cs3Bi2Br9 (11.2 ± 0.4 μmole- g-1 h-1) and bulk g-C3N4 (5.5 ± 0.5 μmole- g-1 h-1). The experimentally determined energy diagram indicates that rGO acts as a solid redox mediator between g-C3N4 and Cs3Bi2Br9 in a Z-scheme heterojunction configuration, ensuring that the semiconductor (Cs3Bi2Br9) with the shallowest conduction band drives the reduction and the one with the deepest valence band (g-C3N4) drives the oxidation. The successful formation of this high-performance heterojunction underscores the potential of the developed composite as a photocatalyst for CO2 reduction, offering promising prospects for advancing the field of solar fuels and achieving sustainable energy goals.

Spacer Engineering Enables Fine-Tuned Thin Film Microstructure and Efficient Charge Transport for Ultrasensitive 2D Perovskite-Based Heterojunction Phototransistors and Optoelectronic Synapses.

2D Ruddlesden-Popper phase layered perovskites (RPLPs) hold great promise for optoelectronic applications. In this study, a series of high-performance heterojunction phototransistors (HPTs) based on RPLPs with different organic spacer cations (namely butylammonium (BA+), cyclohexylammonium (CyHA+), phenethylammonium (PEA+), p-fluorophenylethylammonium (p-F-PEA+), and 2-thiophenethylammonium (2-ThEA+)) are fabricated successfully, in which high-mobility organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene is adopted to form type II heterojunction channels with RPLPs. The 2-ThEA+-RPLP-based HPTs show the highest photosensitivity of 3.18 × 107 and the best detectivity of 9.00 × 1018 Jones, while the p-F-PEA+-RPLP-based ones exhibit the highest photoresponsivity of 5.51 × 106 A W-1 and external quantum efficiency of 1.32 × 109%, all of which are among the highest reported values to date. These heterojunction systems also mimicked several optically controllable fundamental characteristics of biological synapses, including excitatory postsynaptic current, paired-pulse facilitation, and the transition from short-term memory to long-term memory states. The device based on 2-ThEA+-RPLP film shows an ultra-high PPF index of 234%. Moreover, spacer engineering brought fine-tuned thin film microstructures and efficient charge transport/transfer, which contributes to the superior photodetection performance and synaptic functions of these RPLP-based HPTs. In-depth structure-property correlations between the organic spacer cations/RPLPs and thin film microstructure/device performance are systematically investigated.

Interfacial built-in electric field and crosslinking pathways enabling WS2/Ti3C2Tx heterojunction with robust sodium storage at low temperature

Developing efficient energy storage for sodium-ion batteries (SIBs) by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging. Besides, sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates. Herein, cross-linking nanoarchitectonics of WS2/Ti3C2Tx heterojunction, featuring built-in electric field (BIEF), have been developed, employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity. Particularly, the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti3C2Tx to layered WS2, spontaneously forming the BIEF and “ion reservoir” at the heterogeneous interface. Besides, the generation of cross-linking pathways further promotes the transportation of electrons/ions, which guarantees rapid diffusion kinetics and excellent structure coupling. Consequently, superior sodium storage performance is obtained for the WS2/Ti3C2Tx heterojunction, with only 0.2% decay per cycle at 5.0 A g−1 (25 °C) up to 1000 cycles and a high capacity of 293.5 mA h g−1 (0.1 A g−1 after 100 cycles) even at −20 °C. Importantly, the spontaneously formed BIEF, accompanied by “ion reservoir”, in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.

Fabrication of lead oxide nanoparticles by green synthesis method for photovoltaic applications

PbO NPs have been prepared by green synthesis. The diffraction patterns of α-PbO-NPs are shown by the XRD pattern, and the β-PbO-NPs have proven the tetragonal and orthorhombic structure. PbO has an optical energy gap of 4.2 eV. The FT-IR observed bond at 676 cm-1 attributed to the existence of PbO stretch. Nanoparticals with spherical and semi-spherical shapes are formed, as seen in the SEM image. The average particle size was under 100 nm. Fabrication and characterization of a high performance Ag/PbO/PSi/pSi/Ag heterojunction photodetector. The photodetector's responsivity was 0.7 A/W at 850 nm. The maximum detectivity and quantum efficiency spectra 1.009 ×1013 at 850 nm and 3×102 at 200nm which indicates that PbO NPs made using this technique have a good chance of being used to create porous silicon photodetectors with high performance heterojunctions.

Amide Covalent Bonding Engineering in Heterojunction for Efficient Solar-Driven CO2 Reduction.

Inefficient charge separation and slow interfacial reaction dynamics significantly hamper the efficiency of photocatalytic CO2 reduction. Herein, a facile EDC/NHS-assisted linking strategy was developed to enhance charge separation in heterojunction photocatalysts. Using this approach, we successfully synthesized amide-bonded carbon quantum dot-g-C3N4 (CQD-CN) heterojunction photocatalysts. The formation of amide covalent bonds between CN and CQDs in the CN-CQD facilitates efficient carrier migration, CO2 adsorption, and activation. Exploiting these advantages, the CN-CQD photocatalysts exhibit high selectivity with CO and CH4 evolution rates of 79.2 and 2.7 μmol g-1 h-1, respectively. These rates are about 1.7 and 3.6 times higher than those of CN@CQD and bulk CN, respectively. Importantly, the CN-CQD photocatalysts demonstrate exceptional stability, even after 12 h of continuous testing. The presence of the COOH* signal is identified as a crucial intermediate species in the conversion of CO2 to CO. This study presents a covalent bonding engineering strategy for developing high-performance heterojunction photocatalysts for efficient solar-driven reduction of CO2.

Electronic-supply crystal facet guiding enhancement of interfacial charge transfer in homologous covalent heterojunction NiO/Ni-BDC for efficient photocatalytic CO2 reduction

Heterojunction engineering has been an effective strategy to improve separation of charge carriers and photocatalytic activity of semiconductor photocatalysts. Where and how to build effective interface connections for facilitating interface charge migration has always been the key to the construction of high-performance heterojunction. Here, a series of covalently linked homologous heterojunction photocatalysts NiO(111)/Ni-BDC (Ni-BDC = Ni3(BDC)2(OH)2(H2O)4; H2BDC = terephthalic acid) were fabricated by H2BDC in-situ etching octahedral NiO(111) and fully characterized, which were used for photocatalytic reduction of CO2 (pCO2RR) into CH4 and CO. The NiO(111)/Ni-BDC-3 with a proper component proportion and etching degree exhibited an optimal pCO2RR performance with an electron consumption rate (Rele) of 222.68 μmol·g−1·h−1, an excellent CH4 production rate of 21.32 μmol‧g−1‧h−1 and a 76.6% CH4 selectivity, being far superior to most oxide/inorganic semiconductor and oxide/MOF heterojunctions. Comprehensive investigations with extensive photoelectric characterizations, control experiments and DFT calculations based on the homologous NiO(100)/Ni-BDC and non-homologous NiO(100)-Ni-BDC heterojunctions demonstrated that the excellent photocatalytic activity and methane selectivity of NiO(111)/Ni-BDC-3 could be attributed to two points: i) The homologous coordination etching forms a full range of interfacial covalent connections to promote tight MOF-semiconductor integration, yielding a large number of atomic-level electron transfer channels to accelerate the interfacial charge transfer; ii) the alternating polar Ni-O-Ni layer arrangement in NiO(111) crystal facet induces high-throughput electron supply and the enhanced surface charge density effectively promotes the 8-electron reduction process of methane production. Additionally, the durability of NiO(111)/Ni-BDC-3 and the possible charge-transfer mechanisms were also systematically investigated.

Atomic-level investigation on significance of photoreduced Pt nanoparticles over g-C3 N4 /bimetallic oxide composites.

Designing an effective photocatalyst for solar-to-chemical fuel conversion presents significant challenges. Herein, g-C3 N4 nanotubes/CuCo2 O4 (CN-NT-CCO) composites decorated with platinum nanoparticles (Pt NPs) were successfully synthesized by chemical and photochemical reductions. The size distribution and location of Pt NPs on the surface of CN-NT-CCO composites were directly observed by TEM. Extended X-ray absorption fine structure (EXAFS) spectra of Pt L3-edge for the above composite confirmed establishment of Pt-N bonds at an atomic distance of 2.09 Å in the photoreduced Pt-bearing composite, which was shorter than in chemically reduced Pt-bearing composites. This proved the stronger interaction of photoreduced Pt NPs with the CN-NT-CCO composite than chemical reduced one. The H2 evolution performance of the photoreduced (PR) Pt@CN-NT-CCO (2079 μmol h-1 g-1 ) was greater than that of the chemically reduced (CR) Pt@CN-NT-CCO composite (1481 μmol h-1 g-1 ). The abundance of catalytically active sites and transfer of electrons from CN-NT to the Pt NPs to participate in the hydrogen evolution are the primary reasons for the improved performance. Furthermore, electrochemical investigations and band edge locations validated the presence of a Z-scheme heterojunction at the Pt@CN-NT-CCO interface. This work offers unique perspectives on the structure and interface design at the atomic level to fabricate high-performance heterojunction photocatalysts.

The construction of lattice-matched CdS-Ag2S heterojunction photocatalysts: High-intensity built-in electric field effectively boosts bulk-charge separation efficiency

The built-in electric field of heterojunction can effectively promote carrier separation and transfer. While, its interface orientation is often random, leading to lattice mismatch and high resistance, thus limiting the efficiency of interfacial charge transfer. Herein, the lattice-matched heterojunction (CdS-Ag2S) was constructed by ion-exchange epitaxial growth. The results of surface photovoltage spectroscopy (SPV), transient photovoltage spectroscopy (TPV), and time-resolved photoluminescence (TRPL) show that the lattice-matched heterojunction has higher charge separation efficiency and longer photogenerated carrier lifetime than that of lattice-mismatched one. The lattice-matched CdS-Ag2S has a high built-in electric field (BIEF) value of 103.42 and a bulk-charge separation (BCS) efficiency of 68.71%, which is about three times higher than that of the lattice-mismatched heterojunction (CdS-Ag2S-M). In addition, the photodegradation efficiency of CdS-Ag2S towards norfloxacin (NOR) was also 3.4 times higher than that of CdS-Ag2S-M. The above results and density functional theory (DFT) calculations indicate that improving the lattice matching at the heterojunction is beneficial for establishing a high-intensity built-in electric field and effectively promoting bulk-charge separation efficiency, thus achieving excellent photocatalytic performance. This work provides an essential reference for the research of high-performance heterojunction photocatalysts.

Exploring the structural, optoelectronic, elastic, and thermoelectric properties of cubic ternary fluoro-perovskites sodium based NaMF3 (M = Si and Ge) compounds for heterojunction solar cells applications

In the current research, the structural, optoelectronic, elastic, and thermoelectric properties of NaMF3 (M = Si and Ge) ternary halide perovskites compounds are computed within the DFT framework using first-principle modeling. The obtained results of phonons dispersion curves and the tolerance factor is calculated for NaSiF3 and NaGeF3 and is found to be 1.001 and 1.004 respectively, which reveals that these compounds are structurally and thermodynamically stable in the cubic phase. The elastic constants and other mechanical parameters demonstrate that these compounds are mechanically stable, hard to scratch, ductile, anisotropic, and possess resistance to plastic distortion. The band structure and density of states (DOS) demonstrate that NaSiF3 and NaGeF3 compounds are semiconductors and possess a direct band gap of 1.15 eV and 3.31 eV respectively from ‘R-R’ symmetries points. The optical properties are investigated and it is observed that the selected compounds possesses strong optical conduction and absorption coefficients and are transparent at low incident photons energy ranges. This led us to the conclusion that for high-fRequency UV devices, these compounds possess suitable applications. The thermoelectric properties indicate that both materials possess notable power factors and figures of merit (ZT), due to which their applications in solar cells can be deemed. To our knowledge, this is the first theoretical computational systematic study of structural, optoelectronic, elastic, and thermoelectric properties for NaMF3 (M = Si and Ge), which will be experimentally validated. Our findings add comprehensive insight into predicting high-performance Heterojunction Solar Cells.

NaCl sealing Strategy-Assisted synthesis CoO-Co heterojunctions as efficient oxygen electrocatalysts for Zn air batteries

Developing highly efficient, low-cost, and stable bifunctional oxygen electrocatalysts is essential for the wide popularization of rechargeable Zn-air batteries. Combining zero-dimensional metal nanoparticles with two-dimensional metal oxide nanosheets is an appealing strategy to balance performance and cost. However, the precise construction of these composites remains a great challenge, and their interaction mechanisms lack thorough study. Herein, a cobalt-oxide-based bifunctional oxygen electrocatalyst comprising a rich Co-CoO heterointerface (CoO/Co@NG) was synthesized via a NaCl sealing-assisted pyrolysis strategy. The NaCl crystals played the role of a closed nanoreactor, which facilitated the formation of a CoO-Co heterojunction. Experimental results and theoretical calculations confirmed that the ingeniously constructed heterojunction expedited the oxygen reduction reaction and oxygen evolution reaction kinetics, which is superior to Pt/C. When serving as the air electrode in an assembled liquid-state Zn-air battery, the battery shows high power density (215 mW cm−2), specific capacity (710 mAh gzn−1), and outstanding durability (720 h at 10 mA cm−2). This work provides an innovative avenue to design high-performance heterojunction electrocatalysts for perdurable Zn-air batteries.

Construction of Co3 O4 /ZnO Heterojunctions in Hollow N-Doped Carbon Nanocages as Microreactors for Lithium-Sulfur Full Batteries.

Lithium-sulfur (Li-S) batteries are promising alternatives of conventional Li-ion batteries attributed to their remarkable energy densities and high sustainability. However, the practical applications of Li-S batteries are hindered by the shuttling effect of lithium polysulfides (LiPSs) on cathode and the Li dendrite formation on anode, which together leads to inferior rate capability and cycling stability. Here, an advanced N-doped carbon microreactors embedded with abundant Co3 O4 /ZnO heterojunctions (CZO/HNC) are designed as dual-functional hosts for synergistic optimization of both S cathode and Li metal anode. Electrochemical characterization and theoretical calculations confirm that CZO/HNC exhibits an optimized band structure that effectively facilitates ion diffusion and promotes bidirectional LiPSs conversion. In addition, the lithiophilic nitrogen dopants and Co3O4/ZnO sites together regulate dendrite-free Li deposition. The S@CZO/HNC cathode exhibits excellent cycling stability at 2 C with only 0.039% capacity fading per cycle over 1400 cycles, and the symmetrical Li@CZO/HNC cell enables stable Li plating/striping behavior for 400h. Remarkably, Li-S full cell using CZO/HNC as both cathode and anode hosts shows an impressive cycle life of over 1000 cycles. This work provides an exemplification of designing high-performance heterojunctions for simultaneous protection of two electrodes, and will inspire the applications of practical Li-S batteries.

Self-Assembly of Bi2Sn2O7/β-Bi2O3 S-Scheme Heterostructures for Efficient Visible-Light-Driven Photocatalytic Degradation of Tetracycline.

Fabrication of S-scheme heterojunctions with enhanced redox capability offers an effective approach to address environmental remediation. In this study, high-performance Bi2Sn2O7/β-Bi2O3 S-scheme heterojunction photocatalysts were fabricated via the in situ growth of Bi2Sn2O7 on β-Bi2O3 microspheres. The optimized Bi2Sn2O7/β-Bi2O3 (BSO/BO-0.4) degradation efficiency for tetracycline hydrochloride was 95.5%, which was 2.68-fold higher than that of β-Bi2O3. This improvement originated from higher photoelectron-hole pair separation efficiency, more exposed active sites, excellent redox capacity, and efficient generation of ·O2 - and ·OH. Additionally, Bi2Sn2O7/β-Bi2O3 exhibited good stability against photocatalytic degradation, and the degradation efficiency remained >89.7% after five cycles. The photocatalytic mechanism of Bi2Sn2O7/β-Bi2O3 S-scheme heterojunctions was elucidated. In this study, we design and fabricate high-performance heterojunction photocatalysts for environmental remediation using S-scheme photocatalysts.

High-photoresponsivity heterojunction based on MoTe2/2D electron gas at the LaAlO3/SrTiO3 interface

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are ideal elements for many optoelectronic devices owing to their outstanding optoelectrical performance under visible and infrared light. Heterostructures composed of TMDs and other non-TMD materials may exhibit rich properties. In this study, a high-performance heterojunction based on 2D MoTe2 and 2D electron gas (2DEG) at the LaAlO3/SrTiO3 interface was fabricated. The device exhibits good current rectification properties with a high rectification ratio exceeding 103 and a low leakage current (∼1 nA at −6 V bias). Moreover, a high photoresponsivity of ∼800 A W−1 and a large specific detectivity of 4 × 1012 Jones at 405 nm were also obtained at room temperature. Heterostructures based on 2D TMDs and oxide 2DEG are expected to become essential elements in multifunctional microdevices and optoelectronic devices.