Recent Advances in the Solution-Based Preparation of Two-Dimensional Layered Transition Metal Chalcogenide Nanostructures

Bandgap-tuned ultra-small SnO2-nanoparticle-decorated 2D-Bi2WO6 nanoplates for visible-light-driven photocatalytic applications

With the rapid rate of industrialization, the emission of effluents represents a serious threat to aquatic living organisms and the environment. Semiconductor-mediated photocatalysis has been highlighted as the most attractive technology for the elimination of pollutants. In this connection, bandgap-tuned ultra-small SnO₂-nanoparticle-decorated 2D-Bi₂WO₆ nanoplates were prepared via the hydrothermal method. The tuning of the bandgap was altered by the thermal annealing procedure. Moreover, we investigated the influence of different bandgaps of SnO₂ on the anchoring of the 2D-Bi₂WO₆ nanoplates and studied their photocatalytic activity through the degradation of Rhodamine B under visible light irradiation. The ultra-small SnO₂ nanoparticles were highly anchored on the surface of the 2D-Bi₂WO₆ plates, which resulted in more photon harvesting, improved charge separation, the transfer of photoinduced charge carriers, and the alteration of band positions towards the visible region of light. Furthermore, the anchored SnO₂ nanoparticles improved the performance of the photocatalytic activity of 2D-Bi₂WO₆ nanoplates by more than 2.7 times.

Shining light on transition metal sulfides: New choices as highly efficient antibacterial agents

Globally, millions of people die of microbial infection-related diseases every year. The more terrible situation is that due to the overuse of antibiotics, especially in developing countries, people are struggling to fight with the bacteria variation. The emergence of super-bacteria will be an intractable environmental and health hazard in the future unless novel bactericidal weapons are mounted. Consequently, it is critical to develop viable antibacterial approaches to sustain the prosperous development of human society. Recent researches indicate that transition metal sulfides (TMSs) represent prominent bactericidal application potential owing to the meritorious antibacterial performance, acceptable biocompatibility, high solar energy utilization efficiency, and excellent photo-to-thermal conversion characteristics, and thus, a comprehensive review on the recent advances in this area would be beneficial for the future development. In this review article, we start with the antibacterial mechanisms of TMSs to provide a preliminary understanding. Thereafter, the state-of-the-art research progresses on the strategies for TMSs materials engineering so as to promote their antibacterial properties are systematically surveyed and summarized, followed by a summary of the practical application scenarios of TMSs-based antibacterial platforms. Finally, based on the thorough survey and analysis, we emphasize the challenges and future development trends in this area.

Multifunctional layered black phosphorene-based nanoplatform for disease diagnosis and treatment: a review

As an outstanding two-dimensional material, black phosphorene, has attracted significant attention in the biomedicine field due to its large surface area, strong optical absorption, distinct bioactivity, excellent biocompatibility, and high biodegradability. In this review, the preparation and properties of black phosphorene are summarized first. Thereafter, black phosphorene-based multifunctional platforms employed for the diagnosis and treatment of diseases, including cancer, bone injuries, brain diseases, progressive oxidative diseases, and kidney injury, are reviewed in detail. This review provides a better understanding of the exciting properties of black phosphorene, such as its high drug-loading efficiency, photothermal conversion capability, high 1O2 generation efficiency, and high electrical conductivity, as well as how these properties can be exploited in biomedicine. Finally, the research perspectives of black phosphorene are discussed.

Two-dimensional materials in biomedical, biosensing and sensing applications

Two-dimensional (2D) materials are at the forefront of materials research. Here we overview their applications beyond graphene, such as transition metal dichalcogenides, monoelemental Xenes (including phosphorene and bismuthene), carbon nitrides, boron nitrides along with transition metal carbides and nitrides (MXenes). We discuss their usage in various biomedical and environmental monitoring applications, from biosensors to therapeutic treatment agents, their toxicity and their utility in chemical sensing. We highlight how a specific chemical, physical and optical property of 2D materials can influence the performance of bio/sensing, improve drug delivery and photo/thermal therapy as well as affect their toxicity. Such properties are determined by crystal phases electrical conductivity, degree of exfoliation, surface functionalization, strong photoluminescence, strong optical absorption in the near-infrared range and high photothermal conversion efficiency. This review conveys the great future of all the families of 2D materials, especially with the expanding 2D materials' landscape as new materials emerge such as germanene and silicene.

Templated-Construction of Hollow MoS2 Architectures with Improved Photoresponses

Despite the outstanding optoelectronic properties of MoS2 and its analogues, synthesis of such materials with desired features including fewer layers, arbitrary hollow structures, and particularly specifically customized morphologies, via inorganic reactions has always been challenging. Herein, using predesigned lanthanide-doped upconversion luminescent materials (e.g., NaYF4:Ln) as templates, arbitrary MoS2 hollow structures with precisely defined morphologies, widely variable dimensions, and very small shell thickness (≈2.5 nm) are readily constructed. Most importantly, integration of the near-infrared-responsive template significantly improves the photoresponse of up to 600 fold in device made of NaYF4:Yb/Er@MoS2 compared with that of MoS2 nanosheets under 980 nm laser illumination. Multichannel optoelectronic device is further fabricated by simply changing luminescent ions in the template, e.g., NaYF4:Er@MoS2, operating at 1532 nm light excitation with a 276-fold photoresponse enhancement. The simple chemistry, easy operation, high reliability, variable morphologies, and wide universality represent the most important advantages of this novel strategy that has not been accessed before.

In Situ Growth of Tetrametallic FeCoMnNi-MOF-74 on Nickel Foam as Efficient Bifunctional Electrocatalysts for the Evolution Reaction of Oxygen and Hydrogen

Multivariate metal-organic frameworks (MTV-MOFs) have drawn much attention in recent years for their promising applications in many fields of chemistry and materials. Constructing functional MOFs from multiple components for electrochemical water is crucial to high performance renewable energy storage and conversion devices. In this work, a series of bitmetallic-, trimetallic-, and tetrametallic-MOF-74/NFs were grown in situ on nickel foam (NF) by a facile solvothermal route. Specifically, the optimized FeCoMnNi-MOF-74/NF with a multilevel and hollow nanostructure was successfully fabricated and used as highly efficient bifunctional electrocatalysts for water splitting. It exhibited an ultralow overpotential of 250 and 108 mV to achieve the current density of 50 and 10 mA cm^-2, along with the relatively small Tafel slope of 41.28 and 72.89 mV dec^-1 for OER and HER in 1 M KOH, respectively. It is superior to other multimetallic-MOF-74 composites at the same condition and also surpasses the benchmark of commercial noble-metal catalysts as well. As a result, a low cell voltage of ca. 1.62 V was obtained at a current density of 10 mA cm^-2, when tetrametallic FeCoMnNi-MOF-74/NF is employed as both anode and cathode electrodes for the real water splitting. The present work potentially provides a new insight into prospecting and designing multivariate MOFs as a promising material for efficient electrocatalysis in the practical application.

Synthesis of Semiconducting 2H-Phase WTe2 Nanosheets with Large Positive Magnetoresistance

Tungsten ditelluride (WTe₂) is provoking immense interest because of its unique electronic properties, but studies about its semiconducting hexagonal (2H) phase are quite rare. Herein, we report the synthesis of semiconducting 2H WTe₂ nanosheets with large positive magnetoresistance, for the first time, by a simple lithium-intercalation-assisted exfoliation strategy. Systematic characterizations including high-resolution transmission electron microscopy, X-ray diffraction, and Raman and X-ray photoelectron spectroscopies provide clear evidence to distinguish the structure of 2H WTe₂ nanosheets from the orthorhombic (Td) phase bulk counterpart. The corresponding electronic phase transition from metal to semiconductor is also confirmed by density of states calculation, optical absorption, and electrical transport property measurements. Besides, the 2H WTe₂ nanosheets exhibit large positive magnetoresistance with values of up to 29.5% (10 K) and 16.2% (300 K) at 9 T. Overall, these findings open up a promising avenue into the exploration of WTe₂-based materials in the semiconductor field.

Nanoscale Assembly of 2D Materials for Energy and Environmental Applications

Rational design of 2D materials is crucial for the realization of their profound implications in energy and environmental fields. The past decade has witnessed significant developments in 2D material research, yet a number of critical challenges remain for real-world applications. Nanoscale assembly, precise control over the orientational and positional ordering, and complex interfaces among 2D layers are essential for the continued progress of 2D materials, especially for energy storage and conversion and environmental remediation. Herein, recent progress, the status, future prospects, and challenges associated with nanoscopic assembly of 2D materials are highlighted, specifically targeting energy and environmental applications. Geometric dimensional diversity of 2D material assembly is focused on, based on novel assembly mechanisms, including 1D fibers from the colloidal liquid crystalline phase, 2D films by interfacial tension (Marangoni effect), and 3D nanoarchitecture assembly by electrochemical processes. Relevant critical advantages of 2D material assembly are highlighted for application fields, including secondary batteries, supercapacitors, catalysts, gas sensors, desalination, and water decontamination.

IrCo nanocacti on CoxSy nanocages as a highly efficient and robust electrocatalyst for the oxygen evolution reaction in acidic media

Developing highly efficient Ir-based electrocatalysts for the oxygen evolution reaction (OER) has been an important agenda in spearheading the water splitting technology. In this study, the synthesis of IrCo nanocacti on CoxSy nanocages (ICS NCs) is demonstrated by utilizing CoO@CoxSy nanoparticles as reactive nanotemplates. In addition to the high catalytic activities with a low overpotential of 281 mV at 10 mA cm-2 and an outstanding mass activity of 1285 mA mgIr-1 at 1.53 V, the ICS NCs endure a prolonged OER test for over 100 h, greatly outperforming other previously reported Ir-based electrocatalysts. This work suggests that the unique hetero-nanostructure of IrCo/CoxSy induces in situ S doping during electrochemical oxidation and the beneficial effect of S doping on the enhanced stability of ICS NCs for the OER.

Multi-walled carbon-nanotube-decorated tungsten ditelluride nanostars as anode material for lithium-ion batteries

Multi-walled carbon-nanotube (MWCNT)-decorated WTe₂ nanostars (WTe₂@CNT nanocomposites) are to be employed for the first time as anode candidates in the development of lithium-ion (Li-ion) batteries. WTe₂@CNT nanocomposites deliver a high discharge capacity of 1097, 475, 439, 408, 395 and 381 mA h g^-1 with an increasing current density of 100, 200, 400, 600, 800 and 1000 mA g^-1, respectively, while WTe₂ nanostars exhibit a reversible capacity of 655, 402, 400, 362, 290 and 197 mA h g^-1 with the aforementioned current densities. Furthermore, WTe₂@CNT nanocomposites exhibit a superior reversible capacity of 592 mA h g^-1 at 500 mA g^-1 with a capacity retention of 100% achieved over 500 cycles, while bare WTe₂ nanostars deliver ∼85 mA h g^-1 over 350 cycles. This remarkable Li cycling performance is attributed to MWCNTs interconnected with WTe₂ nanostars. In addition, the exposed active interlayers of the WTe₂ nanostars, which are responsible for maintaining the structural integrity of the electrodes, buffer the large volume expansion within the WTe₂ nanostars, avoiding the agglomeration of the particles. The layered WTe₂ nanostars were synthesized via the solution-phase method, and present extremely good possibilities for the scaling-up of Li-ion battery storage systems.

2D materials towards ultrafast photonic applications

Two-dimensional materials are now excelling in yet another arena of ultrafast photonics, including optical modulation through optical limiting/mode-locking, photodetectors, optical communications, integrated miniaturized all-optical devices, etc.

Colloidal Single-Layer Photocatalysts for Methanol-Storable Solar H2 Fuel

Molecular surfactants are widely used to control low-dimensional morphologies, including 2D nanomaterials in colloidal chemical synthesis, but it is still highly challenging to accurately control single-layer growth for 2D materials. A scalable stacking-hinderable strategy to not only enable exclusive single-layer growth mode for transition metal dichalcogenides (TMDs) selectively sandwiched by surfactant molecules but also retain sandwiched single-layer TMDs' photoredox activities is developed. The single-layer growth mechanism is well explained by theoretical calculation. Three types of single-layer TMDs, including MoS₂ , WS₂ , and ReS₂ , are successfully synthesized and demonstrated in solar H₂ fuel production from hydrogen-stored liquid carrier-methanol. Such H₂ fuel production from single-layer MoS₂ nanosheets is CO_x -free and reliably workable under room temperature and normal pressure with the generation rate reaching ≈617 µmole g^-1 h^-1 and excellent photoredox endurability. This strategy opens up the feasible avenue to develop methanol-storable solar H₂ fuel with facile chemical rebonding actualized by 2D single-layer photocatalysts.

Extending the Colloidal Transition Metal Dichalcogenide Library to ReS2 Nanosheets for Application in Gas Sensing and Electrocatalysis

Among the large family of transition metal dichalcogenides, recently ReS₂ has stood out due to its nearly layer-independent optoelectronic and physicochemical properties related to its 1T distorted octahedral structure. This structure leads to strong in-plane anisotropy, and the presence of active sites at its surface makes ReS₂ interesting for gas sensing and catalysts applications. However, current fabrication methods use chemical or physical vapor deposition (CVD or PVD) processes that are costly, time-consuming and complex, therefore limiting its large-scale production and exploitation. To address this issue, a colloidal synthesis approach is developed, which allows the production of ReS₂ at temperatures below 360 °C and with reaction times shorter than 2h. By combining the solution-based synthesis with surface functionalization strategies, the feasibility of colloidal ReS₂ nanosheet films for sensing different gases is demonstrated with highly competitive performance in comparison with devices built with CVD-grown ReS₂ and MoS₂ . In addition, the integration of the ReS₂ nanosheet films in assemblies together with carbon nanotubes allows to fabricate electrodes for electrocatalysis for H₂ production in both acid and alkaline conditions. Results from proof-of-principle devices show an electrocatalytic overpotential competitive with devices based on ReS₂ produced by CVD, and even with MoS₂ , WS₂ , and MoSe₂ electrocatalysts.

Electrochemical exfoliation from an industrial ingot: ultrathin metallic bismuth nanosheets for excellent CO2 capture and electrocatalytic conversion

Formic acid (or formate) is a liquid fuel and chemical feedstock, and it is considered as one of the most useful value-added reductive products from electrochemical CO2 conversion. Green metallic Bi nanosheets are believed be a promising candidate for formic acid production in CO2 electroreduction. However, the complexity of their preparation with a low yield hinders their practical application on a large scale. Herein, we report that by using a cheap and commonly used industrial ingot, phase-pure two-dimensional bismuth nanosheets are fabricated on a large scale by a rapid electrochemical cathodic exfoliation method. In addition to featuring abundant active sites, the obtained Bi nanosheets possess exceptionally high adsorption capacity to CO2 compared to its bulk counterpart, resulting in remarkable enhancement in CO2 electroreduction with high selectivity toward formic acid over a wide range of negative potentials, high current density and satisfactory durability. This facile strategy opens a promising avenue for massive fabrication of metallic Bi nanosheets with excellent electrocatalytic performance for large-scale commercial utilization of CO2.

Homo- and Heterosolvent Modifications of Hofmann-Type Flexible Two-Dimensional Layers for Colossal Interlayer Thermal Expansions

Two-dimensional Hofmann-type coordination polymers of type Mn(H₂O)₂[Pd(CN)₄]·xH₂O (1·xH₂O; x = 0, 1, and 4), Mn(H₂O)(MeOH)[Pd(CN)₄]·2MeOH (2·2MeOH), and Mn(MeOH)₂[Pd(CN)₄]·MeOH (3·MeOH) have been synthesized. The homosolvent-bound 1·4H₂O, 1·H₂O, and 3·MeOH polymers consist of undulating layer structures, whereas the structure of heterosolvent-bound 2·2MeOH consists of "Janus-like" flat layers in which water-bound and MeOH-bound-sides are present. 1·4H₂O and 1·H₂O exhibited anisotropic two-dimensional thermal expansions involving structural transformations of the undulating layers; one layer axis expands while the other contracts. 2·2MeOH exhibits anisotropic thermal expansion in which the flat layers shift sideways as the temperature is increased, with colossal interlayer expansion occurring (α_c = +200 MK^-1 over 140-180 K, α_c = +165 MK^-1 over 200-280 K). 3·MeOH also showed colossal interlayer expansion (α_c = +216 MK^-1) together with expansion of the undulating layers.

Sono-Assisted Surface Energy Driven Assembly of 2D Materials on Flexible Polymer Substrates: A Green Assembly Method Using Water

The challenges in achieving a green and scalable integration of two-dimensional (2D) materials with flexible polymer substrates present a major barrier for the application of 2D materials, such as graphene, MoS₂, and h-BN for flexible devices. Here, we create a sono-assisted surface energy driven assembly (SASEDA) method that can achieve foot-scale to micrometer-scale assembly of 2D materials, form a conductive network in as short as 10 s, and build hierarchical and hybrid flexible devices such as sensors, resistors, and capacitors by using water as the dispersion solvent. SASEDA highlights two counterintuitive innovations. First, we use an "unfavorable" solvent (i.e., water) for both 2D materials (e.g., graphene, MoS₂, and h-BN) and polymer substrates (e.g., polydimethylsiloxane) to drive the assembly process. Second, we use a weak sono-field (0.3 W/cm²) generated by a regular sonication bath cleaner to enhance the assembly efficiency and reorganize and unify the assembly network. This method and its principle pave the way toward affordable large-scale 2D material-based flexible devices.

Facile Bottom-up Preparation of WS2-Based Water-Soluble Quantum Dots as Luminescent Probes for Hydrogen Peroxide and Glucose

Photoluminescent zero-dimensional (0D) quantum dots (QDs) derived from transition metal dichalcogenides, particularly molybdenum disulfide, are presently in the spotlight for their advantageous characteristics for optoelectronics, imaging, and sensors. Nevertheless, up to now, little work has been done to synthesize and explore photoluminescent 0D WS2 QDs, especially by a bottom-up strategy without using usual toxic organic solvents. In this work, we report a facile bottom-up strategy to synthesize high-quality water-soluble tungsten disulfide (WS2) QDs through hydrothermal reaction by using sodium tungstate dihydrate and L-cysteine as W and S sources. Besides, hybrid carbon quantum dots/WS2 QDs were further prepared based on this method. Physicochemical and structural analysis of QD hybrid indicated that the graphitic carbon quantum dots with diameters about 5 nm were held onto WS2 QDs via electrostatic attraction forces. The resultant QDs show good water solubility and stable photoluminescence (PL). The excitation-dependent PL can be attributed to the polydispersity of the synthesized QDs. We found that the PL was stable under continuous irradiation of UV light but can be quenched in the presence of hydrogen peroxide (H2O2). The obtained WS2-based QDs were thus adopted as an electrodeless luminescent probe for H2O2 and for enzymatic sensing of glucose. The hybrid QDs were shown to have a more sensitive LOD in the case of glucose sensing. The Raman study implied that H2O2 causes the partial oxidation of QDs, which may lead to oxidation-induced quenching. Overall, the presented strategy provides a general guideline for facile and low-cost synthesis of other water-soluble layered material QDs and relevant hybrids in large quantity. These WS2-based high-quality water-soluble QDs should be promising for a wide range of applications in optoelectronics, environmental monitoring, medical imaging, and photocatalysis.

Ex-Situ Synthesis and Study of Nanosized Mo-Containing Catalyst for Petroleum Residue Hydro-Conversion

This study represents the results of ex-situ synthesis and research of the properties of concentrated suspensions with new catalysts for petroleum residue hydro-conversion. Suspensions were prepared and stabilized in a petroleum residue medium through reverse emulsions containing water-soluble Mo-precursor and S-containing agents (elemental sulfur, thiocarbamide) in the absence of a solid carrier. The resulting ex-situ catalyst dispersions had Mo content of 6–10 wt % and contained nanosized and submicron catalyst particles stabilized in a petroleum residue medium. The effects of S-containing agents on the properties of catalytic particles (sulfidation level, dispersity, structural and morphological features) were studied. The synthesis conditions for the optimal ex-situ catalyst providing the lowest coke yield (0.2 wt %) and the highest conversion (55.5 wt %) during petroleum residue hydro-conversion in a single pass mode have been determined.

Quenching-Induced Structural Distortion of Graphitic Carbon Nitride Nanostructures: Enhanced Photocatalytic Activity and Electrochemical Hydrogen Production

Engineered nanomaterials are emerging in the field of environmental chemistry. This study involves the analysis of the structural, electronic, crystallinity, and morphological changes in graphitic carbon nitride (g-C₃N₄), an engineered nanomaterial, under rapid cooling conditions. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller, Fourier transform infrared, Raman, band gap, and Mott-Schottky analyses strongly proved that the liquid N₂-quenched sample of g-C₃N₄ has structural distortion. The photocatalytic efficiency of engineered g-C₃N₄ nanostructures was analyzed through the degradation of reactive red 120 (RR120), methylene blue (MB), rhodamine B, and bromophenol as a representative dye. The photocatalytic dye degradation efficiency was analyzed by UV-vis spectroscopy and total organic carbon (TOC) analysis. The photocatalytic efficiency of g-C₃N₄ under different quenching conditions included quenching at room temperature in ice and liquid N₂. The degradation efficiencies are found to be 4.2, 14.7, and 82.33% for room-temperature, ice, and liquid N₂ conditions, respectively. The pseudo-first-order reaction rate of N₂-quenched g-C₃N₄ is 9 times greater than the ice-quenched g-C₃N₄. Further, the TOC analysis showed that 55% (MB) and 59% (RR120) of photocatalytic mineralization were achieved within a time duration of 120 min by the liquid N₂-quenched g-C₃N₄ nanostructure. In addition, the quenched g-C₃N₄ electrocatalytic behavior was examined via the hydrogen (H₂) evolution reaction in acidic medium. The liquid N₂-quenched g-C₃N₄ catalyst showed a lower overpotential with high H₂ evolution when compared with the other two g-C₃N₄-quenched samples. The results obtained provide an insight and extend the scope for the application of engineered g-C₃N₄ nanostructures in the degradation of organic pollutants as well as for H₂ evolution.

Using ligands to control reactivity, size and phase in the colloidal synthesis of WSe2 nanocrystals

Colloidal synthesis enables size- and phase-tuning of WSe₂ nanocrystals.

Tailoring the physicochemical properties of solution-processed transition metal dichalcogenides via molecular approaches

In this Feature Article we highlight the tremendous progress in solution-processed transition metal dichalcogenides and the molecular approaches employed to finely tune their physicochemical properties.

Recent progress in ligand-centered homogeneous electrocatalysts for hydrogen evolution reaction

Recent advances in metal and metal-free ligand-centred electrocatalytic H₂ evolution have been reviewed.

Enhanced soot oxidation activity over CuO/CeO2 mesoporous nanosheets

CuO/CeO₂ mesoporous nanosheets exhibited superior soot oxidation activity owing to the synergistic effects.

Compositing Two-Dimensional Materials with TiO2 for Photocatalysis

Energy shortage and environmental pollution problems boost in recent years. Photocatalytic technology is one of the most effective ways to produce clean energy—hydrogen and degrade pollutants under moderate conditions and thus attracts considerable attentions. TiO2 is considered one of the best photocatalysts because of its well-behaved photo-corrosion resistance and catalytic activity. However, the traditional TiO2 photocatalyst suffers from limitations of ineffective use of sunlight and rapid carrier recombination rate, which severely suppress its applications in photocatalysis. Surface modification and hybridization of TiO2 has been developed as an effective method to improve its photocatalysis activity. Due to superior physical and chemical properties such as high surface area, suitable bandgap, structural stability and high charge mobility, two-dimensional (2D) material is an ideal modifier composited with TiO2 to achieve enhanced photocatalysis process. In this review, we summarized the preparation methods of 2D material/TiO2 hybrid and drilled down into the role of 2D materials in photocatalysis activities.

XPS and Raman study of the active-sites on molybdenum disulfide nanopetals for photocatalytic removal of rhodamine B and doxycycline hydrochlride

Molybdenum disulfide (MoS₂) nanopetals were successfully synthesized by hydrothermal method (sample without sintering) and then sintered at different temperature (sintered samples). The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen (N₂) adsorption analyses for Brunauer–Emmett–Teller (BET) specific surface area measurements, X-ray photoelectron spectrum (XPS) and Raman spectrum. XRD pattern indicated that the samples can be indexed to hexagonal phase 2H-MoS₂. SEM and TEM images showed that the sintered MoS₂ nanopetals had sizes ranging from 150 to 300 nm with almost the same morphology. The pore structure and surface area were nearly the same for the three sintered MoS₂ nanopetals. Interestingly, XPS and Raman spectra implied that there was a few 1T-phase in the MoS₂ nanopetals which enhanced the photocatalytic performance greatly when sintered at low temperature.

Molybdenum disulfide (MoS₂) nanopetals were successfully synthesized by hydrothermal method (sample without sintering) and then sintered at different temperature (sintered samples).