Sulfide Surface Research Articles

Graphene Chainmail-Enabled Moderate Precatalyst Phase Evolution for Sustainable Polysulfide Electrocatalysis in Li─S Batteries.

The rational design of polysulfide electrocatalysts is of vital importance to achieve longevous Li─S batteries. Notwithstanding fruitful advances made in elevating electrocatalytic activity, efforts to regulate precatalyst phase evolution and protect active sites are still lacking. Herein, an in situ graphene-encapsulated bimetallic model catalyst (CoNi@G) is developed for striking a balance between electrocatalytic activity and stability for sulfur electrochemistry. The layer numbers of directly grown graphene can be dictated by tuning the synthetic duration. Exhaustive experimental and theoretical analysis comprehensively reveals that the tailored graphene chainmail boosts catalytic durability while guaranteeing moderate phase evolution, accordingly attaining a decorated surface sulfidation with advanced catalytic essence. Benefiting from the sustainable polysulfide electrocatalysis, CoNi@G enabled sulfur electrodes to harvest a capacity output of 1276.2mAhg-1 at 0.2 C and a negligible capacity decay of 0.055% per cycle after 1000 cycles at 1.0 C. Such a maneuver can be readily extended to other metallic catalysts including NiFe, CoFe, or Co. The work elucidates the precatalyst phase evolution mechanism through a controllable graphene-armored strategy, offering meaningful guidance to realize durable electrocatalysts in Li─S batteries.

Highly efficient photocatalysis-Fenton degradation of antibiotics and phenol over sulfidated FeOCl under natural sunlight illumination

Sulfidated FeOCl is prepared as a heterogeneous photo-Fenton catalyst. And the surface sulfidation of FeOCl can remarkably accelerate the photoinduced charge separation and transfer, while also increase Fe2+/Fe3+ atomic ratio, leading to the boosted photo-Fenton activity in the presence of H2O2. Under irradiation of natural sunlight (light intensity: ∼80 mW·cm−2), over 10 mg sulfidated FeOCl catalyst with using 20 μL 15 % H2O2, 91.2 % of ofloxacin solution (50 mg·L−1) and 97.5 % of sulfisoxazole solution (60 mg·L−1) can be degraded in 80 min, and 99.6 % of phenol solution (625 mg·L−1) is decomposed in 4 h. Under irradiation of a white Light-Emitting Diode (LED) lamp (light intensity: 5 mW·cm−2), 99.8 % of ofloxacin solution is decomposed after treatment for 4 h. Moreover, this photo-Fenton degradation system displays a stable activity in a wide range of pH (1−10), diverse water bodies, and various coexisting ions with concertation from 1 mM to 500 mM. Moreover, sulfidated FeOCl catalyst coated on a frosted glass sheet exhibits excellent stability for degrading ofloxacin even in seven continuous cycles. Particularly, the non-toxicity of the treated ofloxacin, sulfisoxazole, and phenol solution, have been proven by testing their toxic effects on cabbage seed, bacteria, and human embryonic kidney cell, respectively.

Iron redox shuttling and uptake by silicate minerals on the Namibian mud belt

Anoxic marine sediments represent an important source of bioavailable iron (Fe) to the ocean. The highest sedimentary Fe fluxes are observed in open-marine oxygen minimum zones where anoxic bottom waters are in contact with ferruginous surface sediments. Here, sedimentary Fe release, transport and re-deposition (i.e., Fe shuttling) may generate a lateral pattern of sedimentary Fe enrichment and depletion, which can be used to trace redox-related Fe mobility in the paleo-record. However, depending on the balance between terrigenous and authigenic (i.e., shuttle-related) Fe flux, the stability of bottom water redox conditions as well as post-depositional processes of mineral alteration, the sedimentary fingerprint of an Fe redox shuttle may be obscured and difficult to identify.We investigated sedimentary Fe cycling along two transects across the Namibian mud belt with variable terrigenous sedimentation (23°S < 25°S) and during two seasons with opposing bottom water redox conditions (oxic in austral winter versus anoxic to sulfidic in austral summer). On both transects, substantial benthic Fe fluxes up to −50 µmol m−2 d−1 were inferred based on pore water profiles. The magnitude of these fluxes is comparable to those reported for other open-marine oxygen minimum zones. On the transect at 23°S, Fe source areas with ferruginous surface sediments were clearly separated from Fe sink areas with highly sulfidic surface sediments. Therefore, Fe redox shuttling was reflected by a lateral pattern of reactive Fe depletion and enrichment relative to the terrigenous background sedimentation. By contrast, on the transect at 25°S, benthic Fe fluxes were temporally and spatially more variable and surface sediments were ferruginous or only weakly sulfidic. Therefore, sedimentary Fe depletion and enrichment was less pronounced at 25°S. In the Fe sink area at 23°S, hydrogen sulfide was present at the sediment surface during both sampling campaigns and solid phase data suggest that Fe sulfide minerals represented the main burial phase of reactive Fe. By contrast, at 25°S excess Fe was associated with potassium (K) rather than reduced sulfur. While a differing sediment provenance cannot be ruled out entirely, combined evidence from pore water silica profiles, K to Fe stoichiometric relationships and electron microprobe images suggest that laterally derived excess Fe was incorporated into pre-existing and/or authigenic clay minerals during early diagenesis. Iron uptake by clay minerals may be supported by frequent redox oscillations and sediment mixing preventing preservation of Fe sulfide minerals and promoting Fe and K fixation in clay minerals. The burial fluxes of excess Fe associated with sulfide minerals at 23°S and silicate minerals at 25°S were similar. Our findings thus underscore that neoformation or alteration of silicate minerals can be important processes within the low-temperature marine Fe cycle.

Key role of sulfur in sulfidated zerovalent iron during persulfate activation for the dynamic equilibrium of oxidative radicals including SO4•- and •OH

Surface sulfidation has been widely investigated to effectively enhance the utilization and selectivity of iron electrons for enhanced pollutant reduction. However, there is relatively less knowledge on whether sulfidation facilitates the catalytic oxidation process and the mechanism of enhancement. Therefore, in this study, the role of surface sulfidation in modulating the oxidant decomposition pathway and reactive oxygen species generation was investigated with the sulfidated zerovalent iron (S-ZVI) activated persulfate (PS) system. The results revealed that sulfur on the surface of S-ZVI not only facilitates PS activation to generate more SO4•-, but also acts as an essential in the dynamic equilibrium between SO4•- and •OH. Specifically, the S-ZVI surface sulfide first forms sulfur monomers during catalysis, which promotes electron transfer to accelerate Fe3+ to Fe2+ cycling, prompting the generation of more SO4•- also generates SO32−. Then, SO32− is further reacted with •OH to generate the [O−-O-SO3-] intermediate of SO4•-, which leads to a dynamic equilibrium of SO4•- and •OH, mitigating the further conversion of SO4•- to •OH. These findings unveiled the dynamic variation of sulfur on the surface of S-ZVI during PS activation, elevating new insights for the sulfate radical-based efficient degradation.

Open-Circuit Technology of Zinc Oxide Ore Flotation with Ternary Collector and Its Adsorption Characteristics on Smithsonite Surface

The sulfidization-amine flotation method is commonly used for the beneficiation of zinc oxide ores. Lanping zinc oxide ores contains 8.40% zinc, with the main mineral being smithsonite; additionally, they have a high mud content. Conventional sulfidization–ammonium flotation presents a low flotation index and unsatisfactory flotation froth. A new open-circuit technology is employed to treat Lanping zinc oxide ores, where Na2S, KG-248, and dodecyl amine + sodium isoamyl xanthate + ammonium dibutyl dithiophosphate are used as the regulator, depressant, and ternary collector, respectively. Consequently, the flotation indices for the zinc grade and recovery are 28.71% and 86.24%, respectively, and the flotation froth becomes more stable. Subsequently, the flotation behavior and adsorption mechanism of smithsonite with a ternary collector are investigated. The flotation recovery of smithsonite increases to 94.40% after treatment with the ternary collector. Surface-analysis results indicate that the ternary collector can synergistically adsorb onto the sulfidized smithsonite surface to enhance its hydrophobicity, thus increasing the floatability of smithsonite. Meanwhile, the total consumption of the collector in the ternary-collector system is lower than that in the binary- or unitary-collector system.

Oxygen vacancy-mediated activation of Zn-O bonds at the S-scheme heterostructure interface for efficient uranium collection and resistance to biological contamination

Efficient reduction of U(VI) to U(IV) during seawater uranium extraction remains a challenge. Here, cerium dioxide quantum dots were bonded to the surface of indium zinc sulfide (ZIS) to form ZIS composite cerium dioxide quantum dots (ZIS/QDs-Ce). The oxygen vacancies are able to activate the Zn-O bonds at the ZIS and QDs-Ce interfaces, thus enabling the constructed S-scheme heterojunction to show great potential in facilitating the separation and transfer of photogenerated carriers. ZIS/QDs-Ce exhibited high anti-bio-pollution activity by generating biotoxic free radical reactive oxygen species (ROS). The photo-induced reduction of uranium by ZIS/QDs-Ce in 10 ppm uranium spiked simulated seawater reached 99.6 %. Oxygen vacancies cause distortions in the crystal field, and the Zn-O bond activation process triggers the movement of ZIS/QDs-Ce from the singlet low-spin state to the stable triplet state, resulting in free-carrier trapping centers and optimized electronic energy band structures. ZIS/QD-Ce has superior uranium extraction capabilities and is highly recommended for uranium extraction from seawater.

Surface sulfidation constructing gradient heterojunctions for high‐efficiency (approaching 18%) HTL‐free carbon‐based inorganic perovskite solar cells

Surface sulfidation constructing gradient heterojunctions for high‐efficiency (approaching 18%) HTL‐free carbon‐based inorganic perovskite solar cells

Sulfidation of Smithsonite via Microwave Roasting under Low-Temperature Conditions

This study employs microwave roasting to decompose smithsonite mineral (zinc carbonate) into zinc oxide, which then reacts with pyrite to sulfurize its surface, forming zinc sulfide. This process is beneficial for the flotation recovery of zinc oxide minerals. The surface sulfidation behavior of smithsonite under low-temperature microwave roasting conditions is examined through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermodynamic calculations. XRD and thermodynamic analysis indicate that smithsonite completely decomposes into zinc oxide at 400 °C. Introducing a small amount of pyrite as a sulfidizing reagent leads to the formation of sulfides on the surface of decomposed smithsonite. XPS analysis confirms that the sulfide formed on the surface is zinc sulfide. SEM analysis reveals that sulfides are distributed on the surface of smithsonite, and the average sulfur concentration increases with the pyrite dosage. Microwave-assisted sulfurization of smithsonite (ZnCO3) was found to significantly enhance its floatability compared to conventional sulfurization methods. The optimal mass ratio of ZnCO3 to FeS2 is approximately 1:1.5, with the best temperature being 400 °C. These findings provide a technical solution for the application of microwave roasting in the efficient recovery of smithsonite through flotation.

An evaluation of pyrite as a component of respirable coal dust

Over the past two decades, the rise in coal worker’s pneumoconiosis has prompted research into the effects of respirable coal dust components. This study explores how coal-pyrites produce hydroxyl radicals (•OH), a reactive oxygen species closely associated with particle toxicity, and assesses the ability of safe chemical additives to reduce •OH production at various pH levels. Promising candidates were evaluated in various solutions, including tap and process waters and simulated lung fluid. We employed electrokinetic measurements, infrared and X-ray photoelectron spectroscopies, and ab initio atomistic simulations to analyze particle surfaces. The study also looked at how surface aging affects •OH production. Our results show that •OH generation of the pyrite varies and is catalyzed by elements like silicon, aluminum, and iron in pyrite. Carboxymethyl cellulose was effective in reducing •OH production by targeting surface sulfide and silicon sites and affecting surface hydration and charge. Atmospheric aging was found to increase •OH production, especially in the pyrite with high iron and silicon and low calcium contents, relative to other samples. This highlights the role of the pyrite surface properties and chemical composition, and the solution pH and composition in •OH generation by coal-pyrites.

Enhancing Sulfidization and Flotation of Smithsonite Using Eco-Friendly Triethanolamine: Insights from Experimental and Simulation Studies.

Triethanolamine (TEA) is a promising eco-friendly alternative to inorganic ammonia for enhancing surface sulfidization and flotation recovery of smithsonite. Micro-flotation experiments revealed an enhancement in smithsonite recovery to 95.21% with TEA modification, comparable to the results obtained using ammonia. The mechanisms behind the ability of TEA to enhance the sulfidization process were investigated through surface analysis and molecular dynamics simulations. TEA modification increased the content of sulfidization products, the proportion of crucial S22- in adsorbed products, and the thickness and size of the sulfidization product layer. The complexation of TEA with Zn sites formed positively charged Zn-TEA complexes that adsorb onto the smithsonite surface. These complexes promoted negatively charged HS- adsorption, creating a multi-layered adsorption structure. Moreover, TEA modification reduced the total energy required for the sulfidization. These findings open up new possibilities for using eco-friendly reagents in mineral processing, highlighting the potential of TEA in green mineral processing practices.

Molecular Models of Atomically Dispersed Uranium at MoS2 Surfaces Reveal Cooperative Mechanism of Water Reduction.

Single atoms of uranium supported on molybdenum sulfide surfaces (U@MoS2) have been recently demonstrated to facilitate the hydrogen evolution reaction (HER) through electrocatalysis. Theoretical calculations have predicted uranium hydroxide moieties bound to edge-sulfur atoms of MoS2 as a proposed transition state involved in the HER process. However, the isolation of relevant intermediates involved in this process remains a challenge, rendering mechanistic hypotheses unverified. The present work describes the isolation and characterization of a uranium-hydroxide intermediate on molybdenum sulfide surfaces using [(Cp*3Mo3S4)UCp*], a molecular model of a reduced uranium center supported at MoS2. Mechanistic investigations highlight the metalloligand cooperativity with uranium involved in the water activation pathway. The corresponding uranium-oxo analogue, [(Cp*3Mo3S4)Cp*U(═O)], was also accessed from the hydroxide cluster via hydrogen atom transfer and from [(Cp*3Mo3S4)UCp*] through an alternative direct oxygen atom transfer. These results provide an atomistic perspective on the reactivity of low-valent uranium at molybdenum sulfide surfaces toward water, modeling key intermediates associated with the HER of U@MoS2 catalysts.

NiMoP2 co-catalyst modified Cu doped ZnS for enhanced photocatalytic hydrogen evolution

The design of a low-cost, efficient and durable co-catalyst for hydrogen evolution is of great significance for improving photocatalytic activity. In this work, a NiMoP2/Cu-ZnS composite photocatalyst was prepared by in-situ growth of NiMoP2 on the surface of copper-doped zinc sulfide (Cu-ZnS). The test results showed that the hydrogen production rate of the optimized NiMoP2/Cu-ZnS under visible light irradiation was significantly improved. Among them, NiMoP2/Cu-ZnS-1 exhibited the highest photocatalytic activity (5.13 mmol·g−1·h−1), which was 2.47 times that of Cu-ZnS and maintained good stability during the reaction. The improvement of hydrogen production performance of the photocatalyst was mainly attributed to the synergistic effect of Cu-ZnS and co-catalyst NiMoP2. The ohmic contact formed between Cu-ZnS and NiMoP2 could improve the separation efficiency of photogenerated carriers and reduce the overpotential of H2 evolution. Besides, NiMoP2 was found to provide the active site for the reduction reaction, and accelerate the transfer efficiency of photogenerated electrons. This strategy opens up a new way for the construction of co-catalyst modified semiconductor materials to improve the photocatalytic hydrogen production rate.

The impact of weather Condition Changes on Vertical Distribution of Sulfides in Lake Maninjau Based on Observation Data

Sulfide is a crucial parameter in volcanic lakes, as its levels and fluctuations in the lake determine the origin of sulfide and the extent of its impact on the lake ecosystem. In stratified lakes, the sulfide produced tends to be retained beneath the oxic layer. The sulfides rise towards the surface as the oxic layer thins triggered by decreased water column thermal stratification. Meanwhile, the strength or weakness of thermal stratification is greatly influenced by weather conditions. Lake Maninjau is a volcanic lake with a relatively high sulfide content. Its vertical distribution in the water column is highly dependent on the stratification of the water column. When stratification disappears, sulfide rises to the surface (locally known as tubo belerang) and has a negative impact on surface biota. The objective of this study is to examine the distribution of sulfides in the water column of Lake Maninjau under two different weather conditions. We perform two surveys to measure physicochemical parameters and sulfide concentration on 26‒29 November 2022 and 25‒26 August 2023 considering the seasonal pattern. We found that air temperatures and sunshine duration combined with precipitation and wind speed drive the thermal stratification of the water column. The lower air temperature, shorter sunshine duration, higher precipitation, and stronger wind speed in the first survey (west monsoon) compared with the second survey (east monsoon) resulted in lower stratification and triggered the elevated sulfide to the surface. In the middle of the lake, the surface sulfide measured during the first survey was 4.16 µg/L. Meanwhile, in the second survey, it was only observed at 1.16 µg/L. The distribution of sulfides within the water column of Lake Maninjau is regulated by the stratification of the water column, a process directly impacted by weather conditions.

Modulating perovskite crystallization and band alignment using coplanar molecules for high-performance indoor photovoltaics

The proper bandgap and exceptional photostability enable CsPbI3 as a potential candidate for indoor photovoltaics (IPVs), but indoor power conversion efficiency (PCE) is impeded by serious nonradiative recombination stemming from challenges in incomplete DMAPbI3 conversion and lattice structure distortion. Here, the coplanar symmetric structure of hexyl sulfide (HS) is employed to functionalize the CsPbI3 layer for fabricating highly efficient IPVs. The hydrogen bond between HS and DMAI promotes the conversion of DMAPbI3 to CsPbI3, while the coplanar symmetric structure enhances crystalline order. Simultaneously, surface sulfidation during HS-induced growth results in the in situ formation of PbS, spontaneously creating a CsPbI3 N-P homojunction to enhance band alignment and carrier mobility. As a result, the CsPbI3&HS devices achieve an impressive indoor PCE of 39.90% (Pin: 334.6 μW cm−2, Pout: 133.5 μW cm−2) under LED@2968 K, 1062 lux, and maintain over 90% initial PCE for 800 h at ∼30% air ambient humidity.

Mastering Surface Sulfidation of MnP-MnO2 Heterostructure to Facilitate Efficient Polysulfide Conversion in Li─S Batteries.

The development of lithium-sulfur (Li─S) batteries has been hampered by the shuttling effect of lithium polysulfides (LiPSs). An effective method to address this issue is to use an electrocatalyst to accelerate the catalytic conversion of LiPSs. In this study, heterogeneous MnP-MnO2 nanoparticles are uniformly synthesized and embedded in porous carbon (MnP-MnO2/C) as core catalysts to improve the reaction kinetics of LiPSs. In situ characterization and density functional theory (DFT) calculations confirm that the MnP-MnO2 heterostructure undergo surface sulfidation during the charge/discharge process, forming the MnS2 phase. Surface sulfidation of the MnP-MnO2 heterostructure catalyst significantly accelerated the SRR and Li2S activation, effectively inhibiting the LiPSs shuttling effect. Consequently, the MnP-MnO2/C@S cathode achieves outstanding rate performance (10C, 500mAhg-1) and ultrahigh cycling stability (0.017% decay rate per cycle for 2000 cycles at 5C). A pouch cell with MnP-MnO2/C@S cathode delivers a high energy density of 429Whkg-1. This study may provide a new approach to investigating the surface sulfidation of electrocatalysts, which is valuable for advancing high-energy-density Li-S batteries.

Insights into the function of metallic 1T phase tungsten disulfide as cocatalyst decorated zinc indium sulfide for enhanced photocatalytic hydrogen production activity

Improving the separation efficiency of carriers is an important part of enhancing photocatalytic activity. Herein, we successfully decorated metallic 1T phase tungsten disulfide (1T-WS2) on the surface of zinc indium sulfide (ZnIn2S4) and investigated the synergistic effect of 1T-WS2 on ZnIn2S4. The characterization results show that 1T-WS2 improves the light absorption capacity and utilization efficiency, increases the catalytic active site, improves the photogenerated charge separation efficiency, and optimizes the reduction potential of ZnIn2S4. Theoretical calculations show that compared with ZnIn2S4, 1T-WS2/ZnIn2S4 has a smaller adsorption Gibbs free energy of the intermediate state H*, which is conducive to the catalytic reaction. Under simulated solar irradiation, the hydrogen (H2) production rate of 1T-WS2/ZnIn2S4 with a loading of 12 wt% reaches 30.90 mmol h−1 g−1, which is 3.38 times higher than that of single ZnIn2S4 (9.13 mmol h−1 g−1). In addition, the apparent quantum efficiency of 1T-WS2/ZnIn2S4 with a loading of 12 wt% reaches 21.14 % under monochromatic light at a wavelength of λ = 370 nm. This work analyzes the light absorption and carrier separation to the catalytic site, and elucidates the mechanism for the enhancement of the photocatalytic hydrogen production performance.

Experimental and DFT study of modified malachite with 2,5-dimercapto-1,3,4-thiadiazole and its response to sulfidization-xanthate behavior

Malachite is industrially recovered using sulfidization–xanthate flotation. However, due to the instability of the sulfidization effect, it is necessary to strengthen the sulfidization process. To this end, a 2,5-dimercapto-1,3,4-thiadiazole (DMTD) can modify the malachite surface for enhanced sulfidization. Analysis of the sulfidization products indicated that more of highly active Cu2S(Cu(I))species and polysulfides (Sn2−) were found, indicating that the DMTD-modified malachite surface facilitated the adsorption of S components and improved the surface reactivity. Analysis of the sulfidized surface revealed that DMTD and Na2S together increased the ionic strength of S, further confirming that the DMTD-modified malachite surface facilitates S adsorption. Density Functional Theory (DFT) simulates implicate that the intensified sulfidization of malachite surface is due to the resultant of Cu-S products with various degrees of binding and enhanced interactions between S and Cu atoms. Analysis of the sulfidization efficiency of malachite surface confirmed that the DMTD-modified surface adsorbed additional -S components. Changes in the surface potential and contact angle of malachite suggested that the DMTD-modified surface was higher hydrophobic owing to strong adsorption of xanthate. Flotation experiments confirmed that DMTD can improve the sulfidization-xanthate floatability.

Multiphase Fe-doped Ni3S2/MoOx electrocatalyst prepared by facile one-step hydrothermal for full-cell water splitting: Effect of Mo on physical and electrochemical properties

Herein, we develop a multiphase strategy to improve the HER performance by incorporating the MoOx phase with the addition of MoCl5 during the one-step hydrothermal. Adding MoCl5 at 0.5 mmol (MFN-0.5) yields the best HER performance, with an overpotential of 261 mV at a current density of 100 mA/cm2. The MFN-0.5 catalyst exhibits excellent performance for both HER and OER, enabling it to drive full-cell water splitting with cell potentials of 1.50 and 1.71 V at 10 and 100 mA/cm2, respectively. We further scale up the MFN-0.5 (4 ×4 cm2) for a single stack-cell electrolyzer, requiring a cell potential of 1.85 V to achieve a large current density of 250 mA/cm2. Incorporating the MoOx phase accelerates the water dissociation step and protects the metal sulfide surface from oxidation under anodization in an alkaline environment. Our findings offer a promising approach for developing highly efficient catalysts for electrolytic water-splitting applications.

Modulating the electronic structures of Fe3C-based catalyst by surface sulfidation to facilitate H2O2 activation

The performance of Fe-based heterogeneous Fenton catalysts is apparently affected by the electron density of Fe active site. Herein, we modulate the active site electronic density of the Fe3C-based catalyst by surface sulfidation to improve H2O2 activation property. After sulfidation, the removal of acetaminophen (APAP) increased from 27.1% to 100%, and the degradation rate constant kobs of APAP increased 5.44-fold. Sulfidation enhances the utilization of H2O2 and improves the generation of active species. Theoretical calculations demonstrated that sulfidation increases the electron density of Fe sites and lowers the band gap between the d-band center and Fermi energy level, facilitating electron transfer and H2O2 activation. The change in cleavage position of H2O2 from O-H to O-O after sulfidation provides additional evidence for the increased generation of •OH. These results elucidate the promoting effect of sulfidation on heterogeneous Fenton catalysts and provide a strategy for improving the performance of catalyst and contaminant removal.

Lead species formation on pure hemimorphite surface and its performance for subsequent sulfidization

Hemimorphite is important-supplementary resource for the commercial zinc production, but it easy loses into tailings due to extreme difficulty for its surface sulfidization. Adding active metal ions after sulfidization have been widely proposed for enhancing hemimorphite floatability, but its desired efficiency in flotation practice has not yet been completely achieved caused by the instability of sulfide layer. Whereas pre-adsorption of active metal ions to modify the hemimorphite surface has strong potential to make up for this shortcoming. Herein, the feasibility and appropriate environment of free Pb&lt;sup&gt;2+&lt;/sup&gt; for modifying the pure hemimorphite surface was evaluated. Subsequently, the performance of Pb&lt;sup&gt;2+&lt;/sup&gt; adsorption for enhancing sulfidization stability and floatability of hemimorphite were investigated. The X-ray photoelectron spectroscopy results indicated that the Pb&lt;sup&gt;2+&lt;/sup&gt; adsorption on hemimorphite surface was achieved through the Pb ions displacement for Zn ions, and it was bond to oxygen-containing groups on hemimorphite surface. Such adsorption was strengthened with the increasing of solution pH, owing to the abundant Pb hydroxyl species precipitated on mineral under alkaline conditions, in term of the results of visual MINTEQ modeling and time-of-flight secondary-ion mass spectrometry. In addition, the X-ray photoelectron spectroscopy results showed dominant Pb hydroxyl species further reacted with sulfur during subsequent sulfidization to generate much more S species than that of without Pb&lt;sup&gt;2+&lt;/sup&gt; pre-modification. Meanwhile, such sulfide layer composed by Pb&lt;sup&gt;2+&lt;/sup&gt; on the mineral surface presented much higher stability than Zn-S species, which was verified via adsorption and desorption tests. As a result, the sulfidization and flotation recovery of hemimorphite increased after Pb&lt;sup&gt;2+&lt;/sup&gt; pre-adsorption.