Regulating Lewis Acidic Sites of 1T-2H MoS2 Catalysts for Solar-Driven Photothermal Catalytic H2 Production from Lignocellulosic Biomass.

Solar-driven photothermal catalytic H2 production from lignocellulosic biomass was achieved by using 1T-2H MoS2 with tunable Lewis acidic sites as catalysts in an alkaline aqueous solution, in which the number of Lewis acidic sites derived from the exposed Mo edges of MoS2 was successfully regulated by both the formation of an edge-terminated 1T-2H phase structure and tunable layer number. Owing to the abundant Lewis acidic sites for the oxygenolysis of lignocellulosic biomass, the 1T-2H MoS2 catalyst shows high photothermal catalytic lignocellulosic biomass-to-H2 transformation performance in polar wood chips, bamboo, rice straw corncobs, and rice hull aqueous solutions, and the highest H2 generation rate and solar-to-H2 (STH) efficiency respectively achieves 3661 µmol·h-1·g-1 and 0.18% in the polar wood chip system under 300 W Xe lamp illumination. This study provides a sustainable and cost-effective method for the direct transformation of renewable lignocellulosic biomass to H2 fuel driven by solar energy.

Development of Self-Doped Monolayered 2D MoS2 for Enhanced Photoresponsivity.

Transition metal dichalcogenides (TMDs) exist in two distinct phases: the thermodynamically stable trigonal prismatic (2H) and the metastable octahedral (1T) phase. Phase engineering has emerged as a potent technique for enhancing the performance of TMDs in optoelectronics applications. Nevertheless, understanding the mechanism of phase transition in TMDs and achieving large-area synthesis of phase-controlled TMDs continue to pose significant challenges. This study presents the synthesis of large-area monolayered 2H-MoS2 and mixed-phase 1T/2H-MoS2 by controlling the growth temperature in the chemical vapor deposition (CVD) method without use of a catalyst. The field-effect transistors (FETs) devices fabricated with 1T/2H-MoS2 mixed-phase show an on/off ratio of 107. Photo response devices fabricated with 1T/2H-MoS2 mixed-phase show ≈55 times enhancement in responsivity (from 0.32 to 17.4 A W-1) and 102 times increase in the detectivity (from 4.1 × 1010 to 2.48 × 1012 cm Hz W-1) compare to 2H-MoS2. Introducing the metallic 1T phase within the 2H phase contributes additional carriers to the material, which prevents the electron-hole recombination and thereby increases the carrier density in the 1T/2H-MoS2 mixed-phase in comparison to 2H-MoS2. This work provides insights into the self-doping effects of 1T phase in 2H MoS2, enabling the tuning of 2D TMDs properties for optoelectronic applications.

Dual MOF-Derived MoS2 /CdS Photocatalysts with Rich Sulfur Vacancies for Efficient Hydrogen Evolution Reaction.

Cocatalyst plays an important role in efficient charge transfer and separation for photocatalysis. Herein, a MoS2 /CdS photocatalyst with MoS2 as cocatalyst was designed by using Mo-MOF and Cd-MOF as precursors. Due to the existence of rich sulfur vacancies and 1T phase, MoS2 shows strong charge capture and transport ability. The photo-generated electrons on conduction band (CB) can be bound by the sulfur vacancy of CdS and effectively transported to MoS2 through the compact interface between the CdS nanoparticles and 2D large-scale MoS2 . The optimal photocatalyst 1 %MoS2 /CdS exhibited dramatically improved photocatalytic hydrogen production activity, which is 28 times that of pristine CdS and even about 2 times that of 1 %Pt/CdS with same loading amount of noble metal Pt. This work highlights the role of Mo-MOF derived MoS2 with 1T-2H phases as a sustainable and prospective candidate of cocatalyst for improving charge separation and photocatalytic stability of MoS2 /CdS composites.

Dual-vacancies modulation of 1T/2H heterostructured MoS2-CdS nanoflowers via radiolytic radical chemistry for efficient photocatalytic H2 evolution.

Precise defect engineering of photocatalysts is highly demanding but remains a challenge. Here, we developed a facile and controllable γ-ray radiation strategy to assemble dual-vacancies confined MoS2-CdS-γ nanocomposite photocatalyst. We showed the solvated electron induced homogeneous growth of defects-rich CdS nanoparticles, while the symbiotic •OH radicals etched flower-like 1T/2H MoS2 substrate surfaces. The optimal MoS2-CdS-γ exhibited a H2 evolution rate of up to 37.80 mmol/h/g under visible light irradiation, which was 36.7 times higher than that of bare CdS-γ, and far superior to those synthesized by hydrothermal method. The microscopic characterizations and theoretical calculations revealed the formation of such unprecedented dual-sulfur-vacancies ensured the tight interfacial contact for fast charge separation. Besides, the existence of 1T-MoS2 phase further improved the conductivity and strengthened the adsorption interaction with H+ intermediate. Therefore, the radiolytic radical chemistry offered a facile, ambient and effective synthetic strategy to improve the catalytic performances of photocatalytic materials.

Heterogeneous interfaces in 3D interconnected networks of flower-like 1T/2H Molybdenum disulfide nanosheets and carbon-fibers boosts superior EM wave absorption.

With the wide application of electromagnetic waves in national defense, communication, navigation and home appliances, the electromagnetic pollution problem is becoming more and more prominent. Therefore, high-performance, and low-density composite wave-absorbing materials have attracted much attention. In this paper, three-dimensional (3D) network structures of flower-like 1T/2H Molybdenum disulfide nanosheets anchored to carbon fibers (1T/2H MoS2/CNFs) were prepared by electrostatic spinning technique and calcination process. The morphology and electromagnetic wave absorption properties were tuned by changing the content of flower-like MoS2. The optimized 1T/2H MoS2/CNFs composite exhibits superior electromagnetic wave absorption with minimum reflection (RLmin) of -42.26 dB and effective absorption bandwidth (EAB) of 6.48 GHz at 2.5 mm. Multi-facts contribute to the super performance. First, the uniquely designed nanosheet and 3D interconnected networks leads to multiple reflection and scattering of electromagnetic waves, which promotes the attenuation of electromagnetic waves. Second, the propriate content of CNFs and MoS2 with different phase regulates its impedance matching characteristic. Third, Numerous heterogeneous interfaces existed between CNFs and MoS2, 1T and 2H MoS2 phase results in interface polarization. Besides, the 1T/2H MoS2 rich in defects induces defect polarization, improving the dielectric loss. Furthermore, the electromagnetic wave absorption performance was proved via radar reflectance cross section simulation. This work illustrates 1T/2H MoS2/CNFs is a promising material for electromagnetic absorption with wide bandwidth, strong absorption, low density, and high thermal stability.

An electrochemiluminescence aptasensor based on Ti3C2 QDs-1T/2H MoS2 nano-hybrid material for the highly sensitive detection of lincomycin.

Developing a highly selective and sensitive analysis strategy for lincomycin (LIN) is of great significance for environmental protection and food safety. Herein, we reported a novel electrochemiluminescence (ECL) aptasensor based on Ti3C2 QDs-1T/2H MoS2 nano-hybrid luminophore for detection of LIN. The hybridization of Ti3C2 QDs and 1T/2H MoS2 endowed nanocomposite with structural and compositional advantages for boosting the ECL performance of QDs by about three times. This enhancement could be attributed to the remarkable electrocatalytic activity and high conductivity exhibited by 1T/2H MoS2. Secondly, the great surface area of 1T/2H MoS2 is conducive to the high dispersion of Ti3C2 QDs, and its good conductivity could promote charge transfer. On the other hand, the excellent catalytic performance of 1T/2H MoS2 could facilitate the reduction of S2O82- to produce more radical, which significantly enhance the ECL signal of Ti3C2 QDs. Given these features, a sensor for detection of LIN was established based on specific recognition between target and aptamer. The sensor showed a good linear relationship (0.05 ng mL-1 ∼100 µg mL-1) with a detection limit as low as 0.02 ng mL-1. It is worth noting that this work has been validated in testing milk samples, exhibiting great potential application prospects in food analysis.

An Investigation of PPy@1T/2H MoS2 Composites with Durable Photothermal-Promoted Effect in Photo-Fenton Degradation of Methylene Blue and in Water Evaporation.

MoS2 has garnered considerable attention as an exceptional co-catalyst that is capable of significantly enhancing the efficiency of H2O2 decomposition in advanced oxidation processes (AOPs). This improvement allows for a reduction in the required amounts of H2O2 and Fe2+. In this study, we investigated the cyclic durability of photo-Fenton catalysts, focusing on the degradation of pollutants through the introduction of PPy into heterogeneous 1T-2H MoS2 units. The resulting photothermal-Fenton catalysts, comprising non-ferrous Fenton catalysts, demonstrated excellent degradation performance for simulated pollutants. In comparison with 1T-2H MoS2, the PPy@1T-2H MoS2 composite exhibited remarkable stability and photothermal enhancement in the photo-Fenton degradation of methylene blue (MB) under visible light irradiation. The photo-Fenton reaction efficiently degraded contaminants, achieving 99% removal within 5 min and 99.8% removal within 30 min. Moreover, the co-catalyst complex displayed enhanced cyclic stability during the photo-Fenton reaction, with a contaminant removal efficiency of 92%, even after the 13th cyclic test. The combined effects of PPy and 1T-2H MoS2 demonstrated improved efficiency in both photocatalytic and photo-Fenton catalytic reactions. Furthermore, PPy@1T-2H MoS2 exhibited outstanding performance in the photothermal evaporation of water, achieving an efficiency of 86.3% under one solar irradiation.

Boosting the electrochemiluminescence of luminol by high-intensity focused ultrasound pretreatment combined with 1T/2H MoS2 catalysis to construct a sensitive sensing platform.

In the luminol-O2 ECL system, O2 as an endogenous coreactant has the advantages of non-toxicity and stability. Improving the efficiency to generate radicals of O2 is a challenge currently. In this work, a strategy combining physical method - ultrasound and nanomaterial with unique physicochemical properties was designed to enhance the ECL signal of luminol-O2 system. Specifically, high-intensity focused ultrasound (HIFU) pretreatment as a non-invasive method could generate ROS (H2O2, O2•-, OH•, 1O2) in situ, triggering and boosting the ECL signal of luminol. In addition, 1T/2H MoS2 with excellent catalytic activity could catalyze the H2O2 produced in situ, accelerate the oxidation of luminol and further enhance the ECL response. At the same time, combined with the catalytic hairpin assembly (CHA) reaction, the constructed ECL biosensing platform showed excellent performance for the detection of miRNA-155. The concentration range of 0.1 fM âˆ¼ 1 nM with the detection limit as low as 0.057 fM were obtained. Furthermore, the ECL biosensor was also successfully applied to the determination of miRNA-155 in human serum samples. The established ECL sensing platform opens up a promising method for the detection of clinical biomarkers.

Activating and optimizing the In-Plane interface of 1 T/2H MoS2 for efficient hydrogen evolution reaction.

Implanting the octahedral phase (1 T) into the hexagonal phase (2H) of the molybdenum disulfide (MoS2) matrix is considered one of the effective methods to enhance hydrogen evolution reaction (HER) performances of MoS2. In this paper, hybrid 1 T/2H MoS2 nanosheets array was successfully grown on conductive carbon cloth (1 T/2H MoS2/CC) via facile hydrothermal method and the 1 T phase content in 1 T/2H MoS2 is regulated to gradually increase from 0 % to 80 %. 1 T/2H MoS2/CC with 75 % 1 T phase content exhibits optimal HER performances. The DFT calculation results show that S atoms in 1 T/2H MoS2 interface exhibit the lowest hydrogen adsorption Gibbs free energies (ΔGH*) compared with other sites. The improvement of HER performances are primarily attributed to activating the in-plane interface regions of the hybrid 1 T/2H MoS2 nanosheets. Furthermore, the relationship between 1 T MoS2 content in 1 T/2H MoS2 and catalytic activity was simulated by a mathematical model, which shows that the catalytic activity presents a trend of increasing and then decreasing with the increase of 1 T phase content.

Visible-light-driven photocatalytic degradation of tetracycline hydrochloride by Z-scheme Ag3PO4/1T@2H-MoS2 heterojunction: Degradation mechanism, toxicity assessment, and potential applications.

Residual antibiotics in wastewater threaten living organisms and the ecosystem, while the photocatalytic process is recognized as one of the most eco-friendly and promising technologies for the treatment of antibiotic wastewater. In this study, a novel Z-scheme Ag3PO4/1T@2H-MoS2 heterojunction was synthesized, characterized, and used for the visible-light-driven photocatalytic degradation of tetracycline hydrochloride (TCH). It was found that Ag3PO4/1T@2H-MoS2 dosage and coexisting anions had significant effects on the degradation efficiency, which could reach up to 98.9 % within 10 min under the optimal condition. Combing experiments and theoretical calculations, the degradation pathway and mechanism were thoroughly investigated. The excellent photocatalytic property of Ag3PO4/1T@2H-MoS2 was achieved attributed to the Z-scheme heterojunction structure, which remarkably inhibited the recombination of photoinduced electrons and holes. The potential toxicity and mutagenicity for TCH and generated intermediates were evaluated, which revealed the ecological toxicity of antibiotic wastewater was reduced effectively during the photocatalytic degradation process.

Heterophase junction engineering: Enhanced photo-thermal synergistic catalytic performance of CO2 reduction over 1T/2H-MoS2.

Photocatalytic CO2 reduction technology has been proposed as a promising solution to the greenhouse effect and energy crisis. However, the lower quantum efficiency limits its practical applications. Here, we have significantly improved the photocatalytic CO2 reduction performance of MoS2 by coupling the heterophase junction (1T/2H-MoS2) construction and photo-thermal synergy strategies. At 200 °C and 42 mW·cm-2 of 420 nm LED irradiation, the CO production rate of 1T/2H-MoS2 reached 35.3 µmol·g-1·h-1, which was 3.5 and 2.8 times that of 1T-MoS2 and 2H-MoS2, respectively. In addition, only faint CO was detected under sole photo- or sole thermal catalysis conditions. Mechanism studies showed that COOH* was the key intermediate in the photo-thermal synergistic catalytic CO2 reduction over 1T/2H-MoS2. The heterophase junction engineering significantly facilitated the separation of photogenerated carriers, and the introduction of heat accelerated the charge migration and surface reaction rates. Our work provides innovative insights into the catalyst design and mechanism studies for photo-thermal synergistic catalytic CO2 reduction.

Sonocatalytic degradation of ciprofloxacin and organic pollutant by 1T/2H phase MoS2 in Polyvinylidene fluoride nanocomposite membrane.

The development of recyclable catalysts with effective properties and stable reusability is great importance for the removal of different types of pollutants in wastewater. Herein, we have synthesized Polyvinylidene fluoride (PVDF) polymer and mixed-phase 1T/2H MoS2 for immobilizing the sonocatalyst material. Techniques such as FESEM, XRD, FTIR, XPS, and UV-vis spectra have been used for analyzing the structural, and morphological properties. The formation of a 1T/2H mixed phase in MoS2 has been revealed by XRD and XPS analysis. Consequently, the sonocatalytic performance of the nanocomposite membrane was investigated through ciprofloxacin (CIP) and organic pollutants (Rhodamine B (RhB)). As a result, MoS2/PVDF (PM4) nanocomposite membrane exhibited a superior sonocatalytic activity with 94.37% and 84.37% of RhB and CIP degradation efficiency with pseudo-first-order kinetic constant (k) of 0.0187 min-1, and 0.0044 min-1. The sonocatalytic property of the nanocomposite membrane is related to 1T/2H mixed-phase and PVDF. Additionally, the metallic based 1T phase MoS2 helps to promote electrons and holes and reduce the recombination rate. Moreover, it promotes the generation of more hydroxy radicals (.OH), and superoxide radicals (∙O2-) play a significant role in sonocatalytic degradation of RhB pollutants. Thus, the improved sonocatalytic degradation of 1T/2H MoS2/PVDF composite membrane exhibited its application in real-time wastewater treatment.

Facile Synthesis of ZnS/1T-2H MoS2nanocomposite for Boosted adsorption/photocatalytic degradation of methylene blue under visiblelight.

Facile solvothermal techniques were used to manufacture ZnS/1T-2H MoS2 nanocomposite (ZMS) with outstanding adsorption-photocatalytic activity. The formed catalyst was characterized by different tools; XRD, HR-TEM, EDX, FTIR, Raman, N2adsorprion/desorption, Zeta potential, PL,and XPS. The analysis provided the formation on mixed phase of metallic 1Tand 2H phases. ZMS has a high porosity and large specific surface area, and it has a high synergistic adsorption-photocatalytic degradation effect for MB, with a removal efficiency of ≈100% in 45 minutes under visible light irradiation. The extraordinary MB removal efficiency of ZMS was attributed not only to the high specific surface area (49.15 m2/g) and precious reactive sites generated by ZMS, but also to the formation of 1T and 2H phases if compared to pristine MoS2 (MS). The best adsorption affinity was induced by the existance of 1T phase. The remarkably enhanced photocatalytic activity of ZMS nanocomposite can be ascribed to the 2D heterostructure which enhances the adsorption for pollutants, provides abundant reaction active sites, extends the photoresponse to visible light region.

Thermal Rectifier and Thermal Transistor of 1T/2H MoS2 for Heat Flow Management.

Thermal rectifiers and thermal transistors are expected to be widely used for efficient thermal management and energy cascade utilization due to their excellent directional thermal management. Two-dimensional micro/nano materials have huge potential in the applications of thermal transistors, thermal logic circuits, and thermal rectifiers owing to the phase transition and thermal rectification phenomenon. Herein, a lithium intercalation method was used to transform 2H-MoS2 into the 1T phase with a purity of 76%, and a suspended microelectrode was applied to measure the thermal conductivity and thermal rectification coefficient of the same MoS2 film with 1T and 2H phases in suit. The thermal conductivity and thermal rectification effect of two-phase MoS2 couple with its phase state and structure were also obtained. The results demonstrate that the thermal conductivities of MoS2 in both 1T and 2H phases decrease with increasing temperature. It is also found that the thermal rectification coefficient has no obvious dependence on the temperature and phase change but the asymmetric structure. Furthermore, a thermal rectifier and transistor with a high thermal rectification effect are designed. The direction and magnitude of heat flow through the samples can be effectively controlled and managed by adjusting the phase, size, and structural asymmetry of the different samples. The maximum thermal rectification coefficient of the thermal rectifiers is up to 0.8.

Three-Dimensional Artificial Transpiration Structure Based on 1T/2H-MoS2/Activated Carbon Fiber Cloth for Solar Steam Generation.

The rise of solar steam generation is an effective strategy to mitigate clean water shortages. However, achieving further improvements in conversion efficiency and stability remains a challenge. Here, 1T/2H-MoS2 nanosheets were uniformly assembled on activated carbon fiber cloth (A-CFC) through a facial hydrothermal method, and a three-dimensional (3D)-artificial transpiration device (ATD) was prepared using the plant transpiration process. The combination of activated carbon fiber cloth and 1T/2H phase MoS2 exhibits high light absorption (∼97.5%), excellent mechanical stability, large evaporation area, and easy escape of vapor. Additionally, the 3D hollow cone of the MoS2/carbon fiber cloth can effectively reduce radiative and convective energy loss and then achieve the enhancement of energy collection from the environment. An outstanding evaporation rate of 1.61 kg·m-2·h-1 with an optimum conversion efficiency of 97% under one sun is reached. Based on the facile fabrication, excellent stability, and high solar conversion efficiency, this nature-inspired design of 3D 1T/2H-MoS2/A-CFC is expected to facilitate large-scale applications for seawater purification and desalination.

Micro-flower like Core-shell structured ZnCo@C@1T-2H-MoS2 composites for broadband electromagnetic wave absorption and photothermal performance.

Core-shell structure has been receiving extensive attention to enhance the electromagnetic wave (EMW) absorption performance due to its unique interface effect. In this paper, a micro-flower like ZnCo@C@1T-2H-MoS2 was prepared through MOF self-template method. The introduction 1T-2H-MoS2 shell helps optimize impedance matching of the CoZn@C particles to improve the EMW absorption ability. The minimal reflection loss (RLmin) value of ZnCo@C@1T-2H-MoS2 is -35.83 dB with a thickness of 5.0 mm at 5.83 GHz and the effective absorption (RL < -10 dB) bandwidth up to 4.56 GHz at 2.0 mm thickness. Meanwhile, the overall effective absorption bandwidth (OEAB) can reach up to 13.44 GHz from 4.56 to 18.0 GHz. Moreover, ultrafast photothermal performances are also achieved, which can guarantee the normal functioning of ZnCo@C@1T-2H-MoS2 materials in cold conditions. The excellent EMW absorption and photothermal performance are attributed to the unique structure designed with the core of magnetic ZnCo@C rhombic dodecahedral and the shell of dielectric micro-flower like 1T-2H-MoS2 optimize impedance matching.

Constructing 1T/2H MoS2 nanosheets/3D carbon foam for high-performance electromagnetic wave absorption.

Three-dimensional (3D) carbon-based materials have attracted growing attention in the field of electromagnetic wave absorption applications. However, their high conductivity results in high dielectric constant, leading to impedance mismatching, and this characteristic finally weakens their electromagnetic wave absorption performance. In this work, 3D carbon foam (3DCF) was successfully prepared by calcining the melamine foam as the carbon framework precursor under N2 atmosphere. Subsequently, 1T-2H MoS2 nanosheets were uniformly assembled on the surface of the 3DCF skeleton through a solvothermal process. The diameter of the 3DCF skeleton was about 1 µm and the thickness of the 1T-2H MoS2 on the surface was about 150 nm. The 3D network brings in many advantages for microwave attenuation, including numerous conductive pathways, excellent impedance matching and multi-polarization processes. The composites exhibited a maximum reflection loss (RLmax) of -45.88 dB at 10.2 GHz with the thickness of 2.2 mm, and the effective absorbing bandwidth (EAB) was as wide as 5.68 GHz, implying their superb microwave absorption behavior. This work is believed to offer a strategy for the design of efficient 3D electromagnetic wave absorbers with low density in the future.

MoS2-Decorated/Integrated Carbon Fiber: Phase Engineering Well-Regulated Microwave Absorber.

Phase engineering is an important strategy to modulate the electronic structure of molybdenum disulfide (MoS2). MoS2-based composites are usually used for the electromagnetic wave (EMW) absorber, but the effect of different phases on the EMW absorbing performance, such as 1T and 2H phase, is still not studied. In this work, micro-1T/2H MoS2 is achieved via a facile one-step hydrothermal route, in which the 1T phase is induced by the intercalation of guest molecules and ions. The EMW absorption mechanism of single MoS2 is revealed by presenting a comparative study between 1T/2H MoS2 and 2H MoS2. As a result, 1T/2H MoS2 with the matrix loading of 15% exhibits excellent microwave absorption property than 2H MoS2. Furthermore, taking the advantage of 1T/2H MoS2, a flexible EMW absorbers that ultrathin 1T/2H MoS2 grown on the carbon fiber also performs outstanding performance only with the matrix loading of 5%. This work offers necessary reference to improve microwave absorption performance by phase engineering and design a new type of flexible electromagnetic wave absorption material to apply for the portable microwave absorption electronic devices.

Controllably Doping Nitrogen into 1T/2H MoS2 Heterostructure Nanosheets for Enhanced Supercapacitive and Electrocatalytic Performance by Low-Power N2 Plasma.

Molybdenum disulfide (MoS2) is a promising candidate for use as a supercapacitor electrode material and non-noble-metal electrocatalyst owing to its relatively high theoretical specific capacitance, Pt-like electronic feature, and graphene-like structure. However, insufficient electrochemically active sites along with poor conductivity significantly hinder its practical application. Heteroatom doping and phase engineering have been regarded as effective ways to overcome the inherent limitations of MoS2 and enhance its ion storage and electrocatalytic performance. In this study, a plasma-assisted nitrogen-doped 1T/2H MoS2 heterostructure has been proposed for the first time, resulting in excellent supercapacitor performance and hydrogen evolution reaction activity. XPS, Raman, and TEM analysis results indicate that N atoms have been successfully doped into MoS2 nanosheets via room-temperature low-power N2 plasma, and the 1T/2H hybrid phase is maintained. As expected, the 1T/2H MoS2 heterostructure after a 10 min plasma treatment displayed a much boosted supercapacitive performance with a high specific capacitance of 410 F g-1 at 1 A g-1 and an excellent hydrogen evolution property with a low overpotential of 131 mV vs RHE at 10 mA cm-2 for hydrogen evolution reaction. The excellent performance is superior to most of the recently reported outstanding MoS2-based electrode and electrocatalytic materials. Moreover, the as-assembled flexible symmetric supercapacitor shows a high specific capacitance of 84.8 F g-1 and superior mechanical robustness with 84.5% capacity retention after 2000 bending cycles.

Edge-Rich Bicrystalline 1T/2H-MoS2 Cocatalyst-Decorated {110} Terminated CeO2 Nanorods for Photocatalytic Hydrogen Evolution.

Developing all-solid-state Z-scheme systems with highly active photocatalysts are of huge interest in realizing long-term solar-to-fuel conversion. Here we reported an innovative hybrid of {110}-oriented CeO2 nanorods with edge-enriched bicrystalline 1T/2H-MoS2 coupling as efficient photocatalysts for water splitting. In the composites, the metallic 1T phase acts as an excellent solid state electron mediator in the Z-scheme, while the 2H phase and CeO2 are the adsorption sites of the photosensitizer and reactant (H2O), respectively. Through optimal structure and phase engineering, 1T/2H-MoS2@CeO2 heterojunctions simultaneously achieve high charge separation efficiency, proliferated density of exposed active sites, and excellent affinity to reactant molecules, reaching a superior hydrogen evolution rate of 73.1 µmol/h with an apparent quantum yield of 8.2% at 420 nm. Furthermore, density functional theory calculations show that 1T/2H-MoS2@CeO2 possesses the advantages of intensive electronic interaction from the built-in electric field (negative MoS2 and positive charged CeO2) and reduced H2O adsorption/dissociation energies. This work sheds light on the design of on-demand noble-metal-free Z-scheme heterostructures for solar energy conversion.