Facile Precipitation Research Articles

Boosting carbon monoxide production during CO2 reduction reaction via Cu-Sb2O3 interface cooperation

Development of multiple-component catalyst materials is a new trend in electrochemical CO2 reduction reaction (eCO2RR). A new type of metal-oxide interaction is reported here to improve carbon monoxide production via synergistic effect between the CO2-to hydrocarbon selective metal material and CO2-to hydrogen generation oxide material. Cu/Sb2O3 material originates from the hetero-structured CuO/Sb2O3 by a facile two-step hydrolysis and precipitation method, cooperative to inhibit hydrogen evolution or methane product, achieving CO Faradaic efficiency to 92% in CO2 saturated KCl electrolyte at −0.99 V with good stability. The formation of a stable *COOH intermediate by electronic and geometric effects via Cu and Sb2O3 are responsible to promote CO selectivity. Cu-Sb2O3 interface interaction also destabilizes the adsorption *H as well, an intermediate for H2 evolution. This study proposes a versatile design strategy for construction and utilization of metal-oxide interface for eCO2RR.

Well-defined Gd(OH)CO3, Gd2O(CO3)2·H2O, and Gd2O3 compounds with multiform morphologies and adjustable particle sizes: Synthesis, formation process, and luminescence properties

A variety of monodisperse size-tunable Gd(OH)CO3 nanospheres and Gd2O(CO3)2·H2O microplates have been synthesized via a facile homogeneous precipitation route with a mixing solvent of isopropanol (IPA) and H2O. The morphology and particle size of the gadolinium compounds can be tuned in a controlled manner by simply adjusting the volume ratio of IPA/H2O in solvent or reaction temperature and time. Both the amorphous Gd(OH)CO3 nanospheres and crystalline Gd2O(CO3)2·H2O microplates have been transformed into cubic phase of Gd2O3 after a calcination process in air. Interestingly, the Gd2O3 products perfectly inherit the well-defined morphology, good unifomity and dispersity of the precursor samples except for a shrinkage in particle size due to crystallization and coalescence at high temperature. The Gd2O3:Eu3+ and Gd2O(CO3)2·H2O:Tb3+ samples show red and green emission colors under ultraviolet excitation, and Gd2O3:Yb,Ln3+ (Ln = Er and Ho) samples exhibit characteristic orange-red and green emissions when excited at near-infrared (NIR) excitation. The morphology- and particle size-dependent luminescence performances of phosphors are studied in detail. Moreover, the light emitting diode (LED) devices fabricated with the corresponding down-conversion or up-conversion phosphors can display dazzling characteristic multicolor emissions, revealing that the as-synthesized luminescent materials have potential application prospect in the fields of LEDs, light display systems, and optoelectronic devices.

Facile fabrication of well-dispersed CuxO nanoneedle on porous carbonized nano sponge and its promising application in the thermal decomposition of ammonium perchlorate

To meet demands of composite solid propellants, seeking a promising material as catalyst for the thermal decomposition of ammonium perchlorate (AP) has drawn attention. Herein, a commercially available nano sponge was used as the carbon source and a novel CuxO/carbonized nano sponge (CuxO/CNS) nanocomposite was successfully prepared via a facile precipitation method followed by a calcination process. CuxO/CNS nanocomposite was a simple sponge carbonization combined with CuxO nanoneedles grown directly on the surface of carbonized sponge substrate. Especially, CuxO nanoneedles looked like grass or leaf, dotted with carbon sponge skeleton. To further deeply evaluate the catalytic effect of CuxO/CNS nanocomposite on the thermal decomposition of AP, DSC technique was carried out. As expected, CuxO/CNS nanocomposite exhibited excellent catalytic effect on the thermal decomposition of AP. In a word, this finding provides a new insight into promising application of new catalysts in AP-based solid propellants.

ZnS quantum dots and Bi metals embedded with two dimensional β-Bi2O4 nanosheets for efficient UV-visible light driven photocatalysis

In this work, the ZnS QDs, Bi/β-Bi2O4 and ZnS/Bi/β-Bi2O4 nanocomposite were synthesized through a facile precipitation, solvothermal and wet impregnation route respectively. The combination of bare ZnS QDs with Bi/β-Bi2O4 nanocomposite exhibits superior photocatalytic activity against toxic pollutants (MB & Rh B) and it’s attributed to the increased light-absorption capacity, efficient charge transfer process, extraordinary exciton separation, less photogenerated electron-hole recombination. The ZnS/Bi/β-Bi2O4 nanocomposite was found to be 3 times more efficient as a photocatalyst than pristine ZnS QDs. Besides, this composite demonstrates good stability for photocatalytic activities, no substantial decomposition of activity is being observed after 5 cycle’s run devoid of a main defeat in their performance. Scavenger test were also implemented in order to appreciate the possible mechanism of photodegradation. This superior photocatalytic activity and stability may offer a new sight in the improvement of a photocatalyst with large efficiency for practical application of wastewater treatment.

Preparation of plasmonic CoS/Ag2WO4 nanocomposites: Efficient visible light driven photocatalysts and enhanced anti-microbial activity

Novel CoS/Ag2WO4 photocatalyst have been synthesized successfully by facile chemical precipitation method under normal pressure. The prepared nano photocatalysts were characterized with UV–vis DRS, TEM, XRD, PL, Raman spectroscopy, EDAX, N2 adsorption-desorption, XPS and FT-IR. The present work describes the enhanced photocatalytic and antimicrobial activity of CoS/Ag2WO4 nanocomposites (NCs). The K value for MB degradation was 0.089 min−1 by CoS/Ag2WO4 which was 8.9 and 3.1 times greater when compared with 0.01 min−1 by Ag2WO4 and 0.028 min−1 by CoS respectively. The broad-spectrum antibacterial property was exhibited by NCs against gram-ve (E. coli) and gram +ve (B. subtilis) bacteria. The NCs showed enhanced photostability and reusability even after six cycles. The scavenging test confirmed that hydroxyl radicals (OH•) were the major species involved in photocatalytic degradation process under visible light irradiation. The results of the present study can be applied in practical application in the area of photocatalysis and antimicrobial applications.

Boosting the Capacitive Performance of Cobalt(II) Phthalocyanine by Non‐peripheral Octamethyl Substitution for Supercapacitors†

Main observation and conclusionIn this paper, pristine cobalt(II) phthalocyanine (CoPc) and non‐peripheral octamethyl substituted CoPc (N‐CoMe2Pc) are the focus of electrochemical investigation. CoPc and N‐CoMe2Pc nanorods (NR) were synthesized by a facile precipitation process from sublimated bulk phthalocyanine powders and their electrochemical properties were explored. Due to the large specific surface area, the capacitance performance of the nanorods was significantly higher than that of the sublimated powder sample. N‐CoMe2Pc powder exhibited better pseudocapacity compared with CoPc powder and CoPc NR, which is attributed to enhanced charge transfer rate and improved redox activity after the introduction of octamethyl substituents on phthalocyanine ring. The maximum specific capacitance value was achieved by N‐CoMe2Pc NR based electrode, exhibiting 210.2 F g–1 capacitance at 5 mV s–1 scan rate and 156.1 F g–1 at 0.25 A g‐1 current density, and also showing high efficiency and satisfactory retention. These results indicate that according to proper molecular design, N‐CoMe2Pc NR could be applied as the potential candidate for electrode material in supercapacitors.

Ag modified Ni x Al y Mn z O 2 polynary metal oxides (Ag@ NAM ) synthesized by a facile precipitation method as bifunctional catalyst for high performance air electrode of lithium‐oxygen batteries

An ideal catalyst material in the air electrode can reduce the over-potentials and obtain an excellent electrochemical performance for lithium-oxygen batteries. In this paper, Ag modified NixAlyMnzO2 polynary metal oxides (Ag@NAM) is synthesized by a facile precipitation method and as a bifunctional catalyst for high performance air electrode of lithium-oxygen batteries. X-ray diffraction and Raman spectrum test results show that the Ag@NAM catalyst has high crystallinity, which can prevent the lattice distortion caused by manganese dissolution and Ag staying on the surface can change the bond energy in order to supply some special catalytic effects. Through scanning electron microscope observation, Ag@NAM with the proportion of Ag and NixAlyMnzO2 polynary metal oxides to 8.5:1.5 has regular block morphology and uniform grain size. When an air electrode catalyst for lithium-oxygen batteries, Ag@NAM can provide a large electrochemical reaction space along with enough oxygen atoms and lithium ions for electrocatalytic and electrochemical reactions. Specific discharge capacities can achieve to 6834.83, 6477.07, and 4357.14 mAh g−1 at 0.1, 0.2, and 0.3 mA cm−2 current densities, respectively. In addition, this air electrode can carry out stable 28-time charge and discharge cycles. Hence, we feel that Ag@NAM catalyst can play an ideal bifunctional catalytic role and effectively reduce the polarization resistance.

Branching TiO2 nanowire arrays for enhanced ethanol sensing

Nanostructure modulation is effective to achieve high performance TiO2-based gas sensors. We herein report a wet-chemistry route to precipitate directly branched TiO2 nanowire arrays on alumina tubes for gas sensing applications. The optimized branched TiO2 nanowire array exhibits a response of 9.2 towards 100 ppm ethanol; whilst those of the pristine TiO2 nanowire array and the branched TiO2 nanowire powders randomly distributed are 5.1 and 3.1, respectively. The enhanced response is mainly contributed to the unique porous architecture and quasi-aligned nanostructure, which provide more active sites and also favor gas migration. Phase junctions between the backbone and the branch of the branched TiO2 nanowire arrays help the resistance modulation as a result of potential barriers. The facile precipitation of quasi-aligned arrays of branched TiO2 nanowires, which are in situ grown on ceramic tubes, thus provides a new economical synthetic route to TiO2-based sensors with excellent properties.

Controllable preparation of Ag2S quantum dots with size-dependent fluorescence and cancer photothermal therapy

Although Ag2S quantum dots (QDs) have attracted extensive attention in the fields of diagnosis and therapy, it is still a challenge to prepare Ag2S QDs with well-controlled size distribution. Herein, size-tunable Ag2S QDs with glutathione (GSH) as ligands were prepared via a facile aqueous precipitation method. The QDs are precisely prepared through carefully controlled growth of Ag2S QDs by varying the heating time. Morphology and structure characterization verify that Ag2S QDs with 2.0–5.8 nm in diameter are coordinated with GSH through thiol group. The as-prepared Ag2S QDs exhibit broad absorption spectra and narrow fluorescence emission spectra in the near-infrared region. Meanwhile, the QDs perform excellent and stable photothermal effect with a photothermal conversion efficiency up to 58.6%. More importantly, it is found that the size of Ag2S QDs has a significant influence on the fluorescence intensity and photothermal effect. The cell viability evaluation in vitro demonstrates that Ag2S QDs have low cytotoxicity to 293 T cells and Hela cells by methyl thiazolyl tetrazolium test. This paper proposes a convenient route to prepare unique Ag2S QDs, which are capable to act as ideal theranostics probes for photothermal therapy and simultaneously monitoring the therapeutic effect for effective cancer treatment.

One-pot synthesis of zinc oxide nanoparticles via chemical precipitation for bromophenol blue adsorption and the antifungal activity against filamentous fungi

In this research, zinc oxide nanoparticles (ZnONPs) were prepared via a facile one-pot chemical precipitation approach and applied in the adsorption of bromophenol blue (BRB) and as antifungal agents against the filamentous fungi and plant pathogens; Alternaria alternata CGJM3078, Alternaria alternata CGJM3006 and Fusarium verticilliodes CGJM3823. The ZnONPs were characterized by the UV–Vis, FTIR, XRD, TGA, BET, SEM, TEM, and EDX techniques, which showed efficient synthesis. The characteristics ZnO UV–Vis absorption band was observed at 375 nm, while the XRD showed an average ZnONPs crystalline size of 47.2 nm. The SEM and TEM images showed an irregular shaped and aggregated porous structure of 65.3 nm average-sized ZnONPs. The TGA showed 22.9% weight loss at 800 °C indicating the high thermal stability of ZnONPs, while BET analysis revealed a surface area, pore volume and pore diameter of 9.259 m2/g, 0.03745 cm3/g and 9.87 nm respectively. The Freundlich, pseudo-second-order, and intra-particle diffusion models showed R2 > 0.9494 and SSE < 0.7412, thus, exhibited the best fit to the isotherm and kinetics models. Thermodynamics revealed feasible, endothermic, random, and spontaneous adsorption of BRB onto the synthesized ZnONPs. The antifungal assay conducted depicts strong antifungal activities against all three tested fungi. Noticeably, ZnONPs (0.002–5 mg/mL) showed maximum activities with the largest zone of inhibition against A. alternata CGJM 3006 from 25.09 to 36.28 mm. This was followed by the strain F. verticilliodes CGJM 3823 (range from 23.77 to 34.77 mm) > A. alternata CGJM3078 (range from 22.73 to 30.63 mm) in comparison to Bleach 5% (positive control). Additionally a model was proposed based on the possible underlying mechanisms for the antifungal effect. This research demonstrated the potent use of ZnONPs for the adsorption of BRB and as effective antifungal agents.

Polyethylene glycol assisted preparation of AgI with enhanced photocatalytic activity

In this work, AgI photocatalysts with significantly enhanced sunlight-driven photocatalytic performance were prepared with the assistance of polyethylene glycol (PEG) via a facile precipitation method. Brunauer-Emmett-Teller (BET), X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–Vis diffuse reflectance spectra (DRS), surface photovoltage spectroscopy (SPS) were used to study the samples. The level of ·O2− was studied using nitroblue tetrazolium (NBT) -·O2− exclusive reaction. The result exhibits that ·O2− is the primary active free radicals. Photocatalytic performance of the photocatalysts for destruction of rhodamine B (RhB) and tetracycline (TC) was evaluated using a 500W Xe lamp as the light source (simulated sunlight). The photocatalytic activity of PEG-AgI is more than 3 times of that of AgI.

Oxygen vacancy induced peroxymonosulfate activation by Mg-doped Fe2O3 composites for advanced oxidation of organic pollutants

Oxygen vacancy engineering has emerged as an effective approach to improve the performance of catalysts for peroxymonosulfate (PMS) activation. Herein, we report a facile precipitation method followed by calcination to synthesize cost-effective and environmentally friendly magnesium-doped hematite (Mg/Fe2O3) composites. Multiple characterization results reveal that the incorporation of Mg can significantly increase the oxygen vacancies and specific surface area of 5%Mg/Fe2O3, leading to a significantly enhanced performance in degrading Rhodamine B (RhB) through PMS activation. In a typical reaction, almost complete RhB (10 mg/L) removal can be achieved by the activation of PMS (0.2 g/L) using 5%Mg/Fe2O3 (0.5 g/L). Moreover, the as-synthesized catalyst exhibits a broad pH working range (3.96–10.69), high stability, and recyclability. The effects of several parameters (e.g., catalyst amount, PMS dosage, solution pH and temperature, and coexisting inorganic anions) on the removal of RhB in the 5%Mg/Fe2O3/PMS system are investigated. A plausible PMS activation mechanism is proposed, and 1O2 and O2− are identified as the predominant reactive species in RhB degradation instead of SO4− and OH. This study provides new insights into the development of highly efficient iron-based catalysts and highlights their potential applications in environmental purification.

Synthesis of an Ag3PO4/Nb2O5 Photocatalyst for the Degradation of Dye

In this work, the photocatalytic performance of Ag3PO4, Nb2O5 and Ag3PO4/Nb2O5 hybrid photocatalysts to degrade methyl orange dye, MO, in an aqueous solution under visible light irradiation was evaluated. The Ag3PO4 and Ag3PO4/Nb2O5 photocatalysts, with various Ag to Nb molar ratios, were prepared using a facile precipitation method. The photocatalysts were characterized by X-ray diffraction, UV–Visible, X-ray Photoelectron, and Photoluminescence spectroscopies. Upon the addition of Ag3PO4, the band gap energy of Nb2O5 decreased from 3.0 eV to 2.7 eV, indicating the possible use of the Ag3PO4/Nb2O5 hybrid photocatalysts under visible light irradiation. All of the prepared Ag3PO4/Nb2O5 catalysts exhibited higher photocatalytic performance than Ag3PO4 in degrading methyl orange dye under 23-watt visible light irradiation. The Ag3PO4/Nb2O5 catalyst, with a mole ratio of 2:1, exhibited the fastest MO degradation rate of 7.3 × 10−2 min−1, which is twice faster than that of Ag3PO4. The catalyst also shows better stability, as it is reusable for up to six experimental cycles while maintaining its photocatalytic activity above 60%.

The Enhancement of Selectivity and Activity for Two-Electron Oxygen Reduction Reaction by Tuned Oxygen Defects on Amorphous Hydroxide Catalysts

Amorphous catalysts, thanks to their unique coordinately unsaturated properties and abundant of defect sites, incline to possess higher activity and selectivity than their crystalline counterparts....

Synthesis and characterization of visible-light-driven La-doped p-n BiOCl/ZnO heterojunction photocatalyst: mechanism investigation of 3-Cholorophenol degradation

Herein, ZnO, BiOCl, lantanium-doped ZnO, BiOCl and BiOCl/ZnO catalysts were prepared using facile precipitation. Samples were characterized by scanning electron microscopy (SEM–EDS), Brunauer–Emmet–Teller (BET), UV–vis diffuse reflectance (UV–vis DRS), photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), and photoluminescence (PL) techniques. Lanthanum has apparently changed the peak of pure ZnO and BiOCl. The defect at the fermi level to investigate photocatalysis was supported by PL. Photocatalytic activity of the prepared catalysis was investigated using 3-cholorophenol (3-CP) under visible light irradiation. La-doped BiOCl/ZnO catalysis showed higher photocatalytic activity. Results were attributed to the inhibition of charges (electrons/holes). Photo-generated holes and superoxide ( $${\mathrm{h}}^{+}, {\mathrm{O}}_{2}^{\bullet-})$$ radicals were main active species during the radical scavenging activity of 3-CP.

Nonenzymatic glucose‐reactive electrodes fabricated from facilely‐precipitated cobalt hydroxide, commercial graphene nanopowder and ionic liquid binder

Fine Co(OH)2 powder was prepared by simple precipitation from aqueous solutions of cobalt sulfate and sodium hydroxide without using sophisticated reagents and/or approaches. The fine powder was homogeneously mixed with protonated betaine bis((trifluoromethyl)sulfonyl)amide ionic liquid ([Hbet][TFSA] IL), an amide-type hydrophobic protic IL, and then dispersed in ethanol with graphene nanopowder for being spin-coated upon screen-printed carbon electrode (SPCE) to prepare the glucose-reactive electrode. Activation of the electrode was essential to expose the glucose-oxidation activity, and the experimental evidences indicated that Co3O4 converted from Co(OH)2 during the activation process was the active species in charge of glucose oxidation. The electrode showed a wide linear dynamic range for glucose from 1 to 1757 µM with a high sensitivity of 632 µA cm− 2 mM− 1 and a detection limit of 1 µM in the electrolyte containing 0.5 M NaOH and 0.1 M NaCl. The electrode showed no response to common interferants, including alcohols, in the concentration the same as to glucose. However, ascorbic acid in the same concentration level showed severe interference but negligible in the physiological level. This study shows that Co(OH)2 prepared by facile precipitation is qualified of being an efficient electrocatalyst precursor for glucose oxidation, and IL is a good binder for immobilizing the electrocatalyst.

Controlled surface functionalization of Ni-S nanostructures for pH-responsive selective and superior pollutants adsorption

Herein, we developed a synthetic strategy to functionalize Ni-S nanostructures (NS) using a facile precipitation method at moderate temperature. The surface functionality of NS is controlled by varying amount of mixed surfactants to achieve the pH-responsive selective adsorption of anionic and cationic dyes and the adsorption of ciprofloxacin (CIP) and tetracycline (TC) antibiotics. Powder XRD diffraction pattern revealed the phase of NS was changed from α-NiS to mixed phases after functionalization. The surface area of functionalized NS was significantly enhanced by ~5 times of that unfunctionalized NS as 6.6 m2g−1 to 30.3 m2g−1. The NS selectively adsorbed methyl orange (MO) at pH 4.5 and methylene blue (MB) at pH 11.5 with separation efficiency values of 94.2% and 97.9% respectively. The maximum adsorption capacity for MO, MB, TC and CIP are obtained as 1526.3, 1031.2, 1540.8 and 632.4 mg g−1, respectively. The electrostatic interaction is predominantly involved in the adsorption of dyes whereas adsorption of antibiotics changed to hydrogen bonding and metal coordination. Thermodynamics parameters indicated exothermic and spontaneous adsorption of dyes. The optimized adsorbent is easily recyclable. Thus, the developed strategy of functionalization of nanostructures unveils a practical approach towards selective and efficient adsorption of organic pollutants.

Highly efficient AgBr/h-MoO3 with charge separation tuning for photocatalytic degradation of trimethoprim: Mechanism insight and toxicity assessment

A highly solar active AgBr/h-MoO3 composite was constructed by a facile precipitation method, and the charge separation tuning was achieved by photoreduction of AgBr. The photoreduced Ag0 on AgBr/h-MoO3 acted as charge transfer bridge to form Z-scheme heterostructure, while the high degree of Ag reduction converted the material into type-II heterostructure. The synthesized optimal material promoted charge separation and visible light activity due to the incorporation of highly solar active AgBr, which showed ca. 2 times activity on trimethoprim (TMP) degradation than h-MoO3. The contribution of reactive species on TMP degradation followed the order of O2− >1O2 > h+, which agree well with the proposed charge separation mechanism. The photocatalytic degradation mechanism of TMP was proposed based on the radical quenching, intermediate analysis and DFT calculation. The toxicity analysis based on QSAR calculation showed that part of the degradation intermediates are more toxic than TMP, thus sufficient mineralization are required to eliminate the potential risks of treated water. Moreover, the material showed high stability and activity after four reusing cycles, and it is applicable to treat contaminants in various water matrix. This work is expected to provide new insight into the charge separation tuning mechanism for the AgX based heterojunction, and rational design of highly efficient photocatalysts for organic contaminants degradation by solar irradiation.

Correlation of enhanced photocurrent with structural and optical properties of Ag–ZnO nanocomposites synthesized by a facile chemical route

In this paper, we report the synthesis of pure ZnO and plasmonic Ag–ZnO nanocomposites by a facile precipitation method. X-ray diffraction analysis is done for the investigation of phase purity of the synthesized samples. The crystallite size and lattice strain of the samples are obtained by Debye-Scherrer and Williamson–Hall analysis. The UV–Vis absorption spectra of the Ag–ZnO nanocomposites reveal an increased optical absorption in the UV region, which suggests that Ag–ZnO nanocomposite can be used as a UV detector. Furthermore, I–V characteristics of the samples have been measured in an applied bias range of -2V–2V under dark and UV illumination (λ = 365 nm). A significant increase in the photocurrent and a three-fold enhancement in the responsivity values in 13.7 wt % Ag–ZnO nanocomposite as compared to the bare ZnO are attributed to the localized surface plasmon resonance phenomena and strain reduction.

Facile homogeneous precipitation method to prepare MnO2 with high performance in catalytic oxidation of ethyl acetate

Altering the urea decomposition rate in the homogeneous precipitation progress enabled the formation of various morphologies of α-MnO 2 . The decrease in crystalline size led to an increase in the surface area and dominance of the (2 1 1) crystal plane. The abundant surface oxygen species and high reducibility related to unsaturated manganese played critical roles in the decomposition of ethyl acetate. • A facile method driven by a synchronous reaction of urea hydrolysis and potassium permanganate reduction was proposed. • Pure α-MnO 2 with various morphologies was obtained by tuning reaction parameters. • Oxygen species on the (2 1 1) crystal plane were found to be most active in oxidation. • The optimal α-MnO 2 catalyst exhibited high and stable catalytic performance. A facile homogeneous precipitation method driven by synchronous reactions of urea hydrolysis and potassium permanganate reduction is proposed for preparation of MnO 2 catalysts. Pure α-MnO 2 nanostructures with different morphologies, including nanowires, nanorods and nanoparticles, were obtained by simply tuning the precipitation conditions. The evolution of materials derived from different preparation conditions was investigated via X-ray diffraction, transmission electron microscopy, N 2 adsorption, X-ray photoelectron spectroscopy, chemisorption and DFT calculations. The precipitation temperature and time significantly influenced the physiochemical properties of as-prepared catalysts. With increasing precipitation temperature and time, the degree of crystallinity, BET surface area and amount of surface-adsorbed oxygen of α-MnO 2 exhibited a substantial increase. The main exposed surface facets varied from (2 0 0), (3 1 0) to (2 1 1) as temperature and time increased. The best precipitation temperature and time were 90 °C and 24 h respectively. The optimal α-MnO 2 catalyst demonstrated 100% conversion of 1000 ppm ethyl acetate under the high space velocity of 78,000 h −1 during a 113-h test at 190 °C, outperforming other manganese oxide catalysts and many typical noble metal catalysts in terms of activity and stability. Experimental results and DFT calculations were consistent and indicated that surface oxygen species originating from the (2 1 1) surface of α-MnO 2 were most active. This study provides important insights for manipulating the morphology of MnO 2 by a facile method and remarkably promoting the performance for ethyl acetate VOC elimination.