Growth Of Nanosheets Research Articles

In-situ growth of g-C3N4 nanosheets on Nb2O5 nanofibers for enhanced performance in photocatalysis and lithium-sulfur battery

A Nb2O5/g-C3N4 composite with a controllable loading amount of g-C3N4 nanosheets is successfully prepared by a combination of electrospinning and the double crucible gas-solid reaction method. During the heat treatment process, the precursor molecules of melamine gas are in-situ polymerized on the surface of Nb2O5 nanofibers to form g-C3N4 nanosheets. The Nb2O5 nanofibers ultralong one-dimensional nanostructure can effectively avoid the aggregations of g-C3N4 and form tight heterojunction interfaces. The optimized Nb2O5/g-C3N4 composite material improved the photocatalytic activity for methylene blue degradation, with a rate constant twice that of Nb2O5 nanofibers and 3.8 times that of pure g-C3N4. Using the combination of DFT theoretical calculations and capture experiments, the transfer mechanism of the Nb2O5/g-C3N4 type-II heterojunction is confirmed. It was found that the d orbital of Nb and the p orbital of N were the main active site of the photocatalytic reaction. Meanwhile, the lithium-sulfur (Li-S) battery assembled with NOCN-8 as the host material exhibited a high initial discharge capacity of 900 mAh g−1 at 0.5 C, and its capacity decay rate was less than 0.1% after 500 cycles. It shows that NOCN-8 can effectively adsorb polysulfide and catalyze the conversion reaction of polysulfide. This work provides a novel route for the synthesis of the Nb2O5/g-C3N4 composite, and has great potential in the development of environmental remediation and energy applications.

Parallel Aluminum-Cobalt Oxide Nanosheet Arrays with High-Temperature Ferromagnetism.

Parallel nanomaterials possess unique properties and show potential applications in industry. Whereas, vertically aligned 2D nanomaterials have plane orientations that are generally chaotic. Simultaneous control of their growth direction and spatial orientation for parallel nanosheets remains a big challenge. Here, a facile preparation of vertically aligned parallel nanosheet arrays of aluminum-cobalt oxide is reported via a collaborative dealloying and hydrothermal method. The parallel growth of nanosheets is attributed to the lattice-matching among the nanosheets, the buffer layer, and the substrate, which is verified by a careful transmission electron microscopy study. Furthermore, the aluminum-cobalt oxide nanosheets exhibit high-temperature ferromagnetism with a 919 K Curie temperature and a 5.22 emu g-1 saturation magnetization at 300 K, implying the potential applications in high-temperature ferromagnetic fields.

Double-sided growth of MoSe2 nanosheets onto hollow zinc stannate (ZnO, ZnSnO3, and SnO2) nanofibers (h-ZTO) for efficient CO2 photoreduction

The design of photocatalysts that encourage the conversion of CO2 into useful chemicals has been a recent topic of interest, owing to the consequences of climate change. This study develops h-ZTO/MoSe2 hybrid photocatalysts with multiple heterojunctions using facile electrospinning followed by a solvothermal method. MoSe2 nanosheets are formed inside and outside the h-ZTO hollow nanofibers (NFs), increasing the number of accessible active sites and improving the light-scattering properties, which are fundamental for improved photocatalytic performance. A hybrid photocatalyst was obtained by adjusting the h-ZTO/MoSe2 ratio, which showed significantly higher photocatalytic activity than pure h-ZTO. The morphology, structural, phase composition, and functional characteristics of the synthesized photocatalysts were investigated using FE-SEM, TEM, XRD, XPS, PL, TR-PL, and PEC. The 10 wt% h-ZTO/MoSe2 hybrid photocatalyst demonstrated the effective photocatalytic transformation of CO2 into CO, H2, and CH4 with yielding rates of 140, 64, and 33 µmolg−1h−1, respectively. Furthermore, it exhibited the highest CO2 photoreduction selectivity of 93%. This extraordinary performance can be attributed to the uniform growth of the MoSe2 on the internal and external walls of the hollow nanofibers, which enhanced their light-scattering capabilities and provided abundant active sites for the activation and desorption of CO2 throughout the reaction.

In-situ growth of MoS2 nanosheets on g-C3N4 nanotube: A novel electrochemical sensing platform for vanillin determination in food samples

The molybdenum disulfide (MoS2) based nanomaterials show outstanding catalytic performance in many electrochemical sensing applications with improved catalytic and electrochemical properties. Novel electrocatalyst developments and their application for food additives monitoring are of significant interest. In this work, we have developed a novel synthesis protocol for graphitic carbon nitride nanotubes decorated MoS2 composite (g-C3N4 NTs@MoS2) using the hydrothermal method and evaluated its electrochemical sensing performance towards vanillin (VN) determination. The electrochemical sensor was accomplished at various electrolytes and optimized parameters to get an enhanced current signal for VN detection. Under the optimized conditions, the sensor obtained wide linear ranges (0.005-458.9 µM), low limit of detection (LOD, 4 nM), and excellent sensitivity (3.48 μA μM−1 cm−2) using differential pulse voltammetry (DPV). Moreover, the practical applicability of the developed sensor was also successfully evaluated in food samples with an excellent recovery rate.

A novel recoverable 1D core-shell cotton fiber@ZnIn2S4 composite with improved photoactivity for H2 evolution under visible light

The problems of low activity, high cost and difficulty in recycle of photocatalysts limit their practical application. Coupling photocatalyst with abundant and natural organic material is one of feasible strategies to achieve high photoactivity and low cost of photocatalysts. Herein, one-dimensional (1D) cotton fiber@ZnIn2S4 (CF@ZIS)·composites with a novel core-shell structure were synthesized by coupling ZIS with inexpensive and natural abundance CF via a simple one-pot hydrothermal process. The microstructure, crystalline structures, optical properties and electrochemical property of CF@ZIS were investigated. ZIS nanosheets were in-situ attached on the CF surface, obtaining the CF@ZIS core-shell structure. This core-shell structure significantly suppressed the self-assembly of ZIS nanosheets made almost all ZIS nanosheets exposed to visible light, improving the utilization of light and meanwhile affording more reactive sites. The as-synthesized CF@ZIS showed improved photoactivity for efficient hydrogen production under visible-light irradiation. By replacing the half ZIS by cheap CF, the CF@ZIS-50 photocatalyst exhibited the optimal visible-light photocatalytic activity, which is 2 times than pure ZIS in hydrogen production. The enhanced photoactivity of CF@ZIS photocatalyst should be attributed to the uniform in-situ growth of ZIS nanosheets on the CF surface, the reduction of CF, and the intimate interface between ZIS and CF, resulting in the boosted separation and transfer of photogenerated charges. Additionally, due to the fibrous morphology of CF, the CF@ZIS photocatalyst showed excellent recoverability and photostability. This work provides a promising approach for designing highly efficient and low cost photocatalysts by using natural organic materials.

Efficient and selective removal of Hg(II) from water using recyclable hierarchical MoS2/Fe3O4 nanocomposites

Developing practical and cost-effective adsorbents with satisfactory mercury (Hg) remediation capability is indispensable for aquatic environment safety and public health. Herein, a recyclable hierarchical MoS2/Fe3O4 nanocomposite (by in-situ growth of MoS2 nanosheets on the surface of Fe3O4 nanospheres) is presented for the selective removal of Hg(II) from aquatic samples. It exhibited high adsorption capacity (∼1923.5 mg g −1), fast kinetics (k2 ∼ 0.56 mg g −1 min−1), broad working pH range (2–11), excellent selectivity (Kd > 1.0 × 107 mL g −1), and great reusability (removal efficiency > 90% after 20 cycles). In particular, removal efficiencies of up to ∼97% for different Hg(II) concentrations (10–1000 μg L −1) in natural water and industrial effluents confirmed the practicability of MoS2/Fe3O4. The possible mechanism for effective Hg(II) removal was discussed by a series of characterization analyses, which was attributed to the alteration of the MoS2 structure and the surface coordination of Hg-S. The accessibility of surface sulfur sites and the diffusion of Hg(II) in the solid-liquid system were enhanced due to the advantage of the expanded interlayer spacing (0.96 nm) and the hierarchical structure. This study suggests that MoS2/Fe3O4 is a promising material for Hg(II) removal in actual scenarios and provides a feasible approach by rationally constructing hierarchical structures to promote the practical applications of MoS2 in sustainable water treatments.

Enhanced electrocatalytic performance for oxygen evolution reaction via active interfaces of Co3O4 arrays@FeO x /Carbon cloth heterostructure by plasma-enhanced atomic layer deposition

Oxygen evolution reaction (OER) is a necessary procedure in various devices including water splitting and rechargeable metal-air batteries but required a higher potential to improve oxygen evolution efficiency due to its slow reaction kinetics. In order to solve this problem, a heterostructured electrocatalyst (Co3O4@FeO x /CC) is synthesized by deposition of iron oxides (FeO x ) on carbon cloth (CC) via plasma-enhanced atomic layer deposition, then growth of the cobalt oxide (Co3O4) nanosheet arrays. The deposition cycle of FeO x on the CC strongly influences the in situ growth and distribution of Co3O4 nanosheets and electronic conductivity of the electrocatalyst. Owing to the high accessible and electroactive areas and improved electrical conductivity, the free-standing electrode of Co3O4@FeO x /CC with 100 deposition cycles of FeO x exhibits excellent electrocatalytic performance for OER with a low overpotential of 314.0 mV at 10 mA cm−2 and a small Tafel slope of 29.2 mV dec−1 in alkaline solution, which is much better than that of Co3O4/CC (448 mV), and even commercial RuO2 (380 mV). This design and optimization strategy shows a promising way to synthesize ideally designed catalytic architectures for application in energy storage and conversion.

Vertical Growth of WO3 Nanosheets on TiO2 Nanoribbons as 2D/1D Heterojunction Photocatalysts with Improved Photocatalytic Performance under Visible Light

We report the construction of 2D/1D heterojunction photocatalysts through the hydrothermal growth of WO3 nanosheets on TiO2 nanoribbons for the first time. Two-dimensional WO3 nanosheets were vertically arrayed on the surface of TiO2 nanoribbons, and the growth density could be simply controlled by adjusting the concentration of the precursors. The construction of WO3/TiO2 heterojunctions not only decreases the band gap energy of TiO2 from 3.12 to 2.30 eV and broadens the photoresponse range from the UV region to the visible light region but also significantly reduces electron–hole pair recombination and enhances photo-generated carrier separation. Consequently, WO3/TiO2 heterostructures exhibit improved photocatalytic activity compared to pure WO3 nanosheets and TiO2 nanoribbons upon visible light irradiation. WO3/TiO2-25 possesses the highest photocatalytic activity and can remove 92.8% of RhB pollutants in 120 min. Both further increase and decrease in the growth density of WO3 nanosheets result in an obvious reduction in photocatalytic activity. The kinetic studies confirmed that the photocatalytic degradation of RhB follows the kinetics of the pseudo-first-order model. The present study demonstrates that the prepared WO3/TiO2 2D/1D heterostructures are promising materials for photocatalytic removal of organic pollutants to produce clean water.

High-Density NiCu Bimetallic Phosphide Nanosheet Clusters Constructed by Cu-Induced Effect Boost Total Urea Hydrolysis for Hydrogen Production.

The development of urea electrolysis technologies toward energy-saving hydrogen production can alleviate the environmental issues caused by urea-rich wastewater. In the current practices, the development of high-performance electrocatalysts in urea electrolysis remains critical. In this work, the NiCu-P/NF catalyst is prepared by anchoring Ni/Cu bimetallic phosphide nanosheets onto Ni foam (NF). In the experiments, the micron-sized elemental Cu polyhedron is first anchored on the surface of the NF substrate to provide more space for the growth of bimetallic nanosheets. Meanwhile, the Cu element adjusted the electron distribution within the composite and formed Ni/P orbital vacancies, which in turn accelerated the kinetic process. As a result, the optimal NiCu-P/NF sample exhibits excellent catalytic activity and cycling stability in a hybrid electrolysis system for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). Further, the alkaline urea-containing electrolyzer is assembled with NiCu-P/NF as two electrodes reached a current density of 50 mA cm-2 with a low driving potential of 1.422 V, which outperforms the typical commercial noble metal electrolyzer (RuO2||Pt/C). Those findings suggest the feasibility of the substrate regulation strategy to increase the growth density of active species in preparation of an efficient bifunctional electrocatalyst for cracking the urea-containing wastewater.

Enhanced Photocatalytic Hydrogen Production of ZnIn2S4 by Using Surface-Engineered Ti3C2Tx MXene as a Cocatalyst.

Developing efficient and stable photocatalysts is crucial for photocatalytic hydrogen production. Cocatalyst loading is one of the effective strategies for improving photocatalytic efficiency. Here, Ti3C2Tx (Tx = F, OH, O) nanosheets have been adopted as promising cocatalysts for photocatalytic hydrogen production due to their metallic conductivity and unique 2D characterization. In particular, surface functionalized Ti3C2(OH)x and Ti3C2Ox cocatalysts were synthesized through the alkalization treatment with NaOH and a mild oxidation treatment of Ti3C2Fx, respectively. ZnIn2S4/Ti3C2Tx composites, which were fabricated by the in-situ growth of ZnIn2S4 nanosheets on the Ti3C2Tx surface, exhibited the promoted photocatalytic performance, compared with the parent ZnIn2S4. The enhanced photocatalytic performance can be further optimized through the surface functionalization of Ti3C2Fx. As a result, the optimized ZnIn2S4/Ti3C2Ox composite with oxygen functionalized Ti3C2Ox cocatalyst demonstrated excellent photocatalytic hydrogen evolution activity. The characterizations and density functional theory calculation suggested that O-terminated Ti3C2Ox could effectively facilitate the transfer and separation of photogenerated electrons and holes due to the formation of a Schottky junction, with the largest difference in work function between ZnIn2S4 and Ti3C2Ox. This work paves the way for photocatalytic applications of MXene-based photocatalysts by tuning their surface termination groups.

S-scheme CuInS2/WO3 hybrid heterostructures as catalysts for visible-light-driven photo-Fenton degradation of tetracycline hydrochloride

Fabricating highly efficient catalysts for the degradation of persistent antibiotics is challenging. Herein, a series of CuInS2/WO3 hybrid heterostructures with different WO3:CuInS2 weight ratios were fabricated via the in situ growth of CuInS2 nanosheets onto WO3 nanoplates surfaces using a solvothermal reaction. The as-fabricated CuInS2/WO3 hybrid heterostructures were used as S-scheme photocatalysts to remove tetracycline hydrochloride (TCH) from water sources via an efficient photo-Fenton reaction. The phase structures and morphology of the as-fabricated CuInS2/WO3 hybrid heterostructures were systematically characterised using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The experiments performed to evaluate the structure–activity relationship for the CuInS2/WO3 hybrid heterostructures demonstrated that an S-scheme mechanism was critical for the highly efficient photo-Fenton degradation of TCH. Moreover, the S-scheme mechanism of the CuInS2/WO3 hybrid heterostructures was confirmed using active species trapping and electron paramagnetic resonance measurements. We believe that our study provides useful insights for the fabrication of highly efficient photo-Fenton catalysts.

Photocatalytic hydrogen evolution from glycerol-water mixture under visible light over zinc indium sulfide (ZnIn2S4) nanosheets grown on bismuth oxychloride (BiOCl) microplates

ZnIn2S4 (ZIS) is one of the widely studied photocatalyst for photocatalytic hydrogen evolution applications due to its prominent visible light response and strong reduction ability. However, its photocatalytic glycerol reforming performance for hydrogen evolution has never been reported. Herein, the visible light driven BiOCl@ZnIn2S4 (BiOCl@ZIS) composite was synthesized by growth of ZIS nanosheets on a template-like hydrothermally pre-prepared wide-band-gap BiOCl microplates using simple oil-bath method to be used for the first time for photocatalytic glycerol reforming for photocatalytic hydrogen evolution (PHE) under visible light irradiation (λ > 420 nm). The optimum amount of BiOCl microplates in the composite was found 4 wt% (4% BiOCl@ZIS) in the presence of in-situ 1 wt% Pt deposition. Then, the in-situ Pt photodeposition optimization studies over 4% BiOCl@ZIS composite showed the highest PHE rate of 674 μmol g-1h−1 with the ultra-low platinum amount (0.0625 wt%). The possible mechanisms behind this improvement can be ascribed to the formation of Bi2S3 low-band-gap semiconductor during BiOCl@ZIS composite synthesis resulting in Z-scheme charge transfer mechanism between ZIS and Bi2S3 upon visible light irradiation. This work expresses not only the photocatalytic glycerol reforming over ZIS photocatalyst but also a solid proof of the contribution of wide-band-gap BiOCl photocatalysts to enhancement of ZIS PHE performance under visible light.

Exploration on the growth of Bi2O2Se films and nanosheet by an ALD-assisted CVD method

Exploration on the growth of Bi2O2Se films and nanosheet by an ALD-assisted CVD method

Scalable Edge-Oriented Metallic Two-Dimensional Layered Cu2Te Arrays for Electrocatalytic CO2 Methanation.

Copper-based nanomaterials are compelling for high-efficient, low-cost electrocatalytic CO2 reduction reaction (CO2RR) due to their exotic electronic and structural properties. However, controllable preparation of copper-based two-dimensional (2D) materials with abundant catalytically active sites, that guarantee high CO2RR performance, remains challenging, especially on a large scale. Here, an in situ vertical growth of scalable metallic 2D Cu2Te nanosheet arrays on commercial copper foils is demonstrated for efficient CO2-to-CH4 electrocatalysis. The edge-oriented growth of Cu2Te nanosheets with tunable sizes and thicknesses is facilely attained by a two-step process of chemical etching and chemical vapor deposition. These active sites abounding on highly exposed edges of Cu2Te nanosheets greatly promote the electroreduction of CO2 into CH4 at a potential as low as -0.4 V (versus the reversible hydrogen electrode), while suppressing hydrogen evolution reaction. When a flow cell is employed to accelerate the mass transfer, the faradaic efficiency reaches ∼63% at an applied current density of 300 mA cm-2. These findings will provide great possibilities for developing scalable, energy-efficient Cu-based CO2RR electrocatalysts.

Dual-pathway optimization on microwave absorption characteristics of core–shell Fe3O4@C microcapsules: Composition regulation on magnetic core and MoS2 nanosheets growth on carbon shell

Core-shell Fe3O4@C composites with unique configuration and complementary loss mechanisms are widely considered as a kind of prospective functional materials in the field of microwave absorption. However, the balance between core–shell configuration and intrinsic loss is always a thorny problem on the way of good microwave absorption characteristics. Herein, we propose a dual-pathway optimization strategy to consolidate the electromagnetic functions of core–shell Fe3O4@C microcapsules for the first time. On one hand, the chemical composition of magnetic core is finely regulated from Fe3O4 to metal Fe, and it is found that both magnetic loss and dielectric loss can be strengthened effectively through the partial reduction of Fe3O4 core. On the other hand, MoS2 nanosheets are closely anchored on the surface of carbon shell, which can bring more powerful interfacial polarization and dipole polarization to compensate the insufficient dielectric loss caused by the limited thickness and graphitization degree of carbon shell. With the multiple benefits from the dual-pathway optimization strategy, the optimal composite will present good microwave absorption performance, whose effective absorption bandwidth (EAB) and minimum RL value are 5.4 GHz (d = 1.8 mm) and −36.1 dB (5.9 GHz, 4.0 mm), respectively. In particular, its specific EABs (EAB per unit thickness) in different bands are superior to those of most microwave absorbing materials with similar chemical composition. These results demonstrate that this dual-pathway optimization will open a new avenue to enhance microwave absorption performance of core–shell composites in the future.

Flexible δ-MnO2 nanosheet-infixed porous carbon nanofibers for capacitive deionization

Birnessite-type manganese dioxide (δ-MnO2) is a typical pseudocapacitive material with the merits of natural abundance, environmental friendliness and high specific capacitance. Herein, the ultrathin δ-MnO2 nanosheets were successfully infixed on the electrospun porous carbon nanofibers (PCNF) by self-limitation reaction. The KMnO4 concentration and the hierarchical pore structure greatly affected the growth of δ-MnO2 nanosheets on the PCNF. Under the optimal condition, the as-prepared flexible δ-MnO2@PCNFs electrode delivered extremely high specific capacitance of 455.3 F g−1. As a cathode in capacitive deionization (CDI), δ-MnO2@PCNF presented the salt adsorption capacity of 15.9 mg g−1, with ultrafast adsorption speed (1.8 mg g−1 min−1). The δ-MnO2@PCNF materials has excellent recycling stability in CDI device due to the interconnected structure of δ-MnO2 nanosheets inserted in PCNF.

General low-temperature growth of two-dimensional nanosheets from layered and nonlayered materials

Most of the current methods for the synthesis of two-dimensional materials (2DMs) require temperatures not compatible with traditional back-end-of-line (BEOL) processes in semiconductor industry (450 °C). Here, we report a general BiOCl-assisted chemical vapor deposition (CVD) approach for the low-temperature synthesis of 27 ultrathin 2DMs. In particular, by mixing BiOCl with selected metal powders to produce volatile intermediates, we show that ultrathin 2DMs can be produced at 280–500 °C, which are ~200–300 °C lower than the temperatures required for salt-assisted CVD processes. In-depth characterizations and theoretical calculations reveal the low-temperature processes promoting 2D growth and the oxygen-inhibited synthetic mechanism ensuring the formation of ultrathin nonlayered 2DMs. We demonstrate that the resulting 2DMs exhibit electrical, magnetic and optoelectronic properties comparable to those of 2DMs grown at much higher temperatures. The general low-temperature preparation of ultrathin 2DMs defines a rich material platform for exploring exotic physics and facile BEOL integration in semiconductor industry.

Metal-organic framework derived nickel‑cobalt layered double hydroxide nanosheets cleverly constructed on interconnected nano-porous carbon for high-performance supercapacitors

The ingenious use of renewable and degradable biomass glucose materials to replace traditional organic synthetic materials can create huge economic benefits and potential ecological environmental protection. In this work, interconnected nano-porous carbon/nickel‑cobalt layered double hydroxide (INPC/NiCo-LDH) composites were successfully fabricated through calcination and solvothermal techniques, by first depositing 2-methylimidazole cobalt salt (ZIF-67) nanoparticles on the surface of INPC using glucose as the carbon source, followed by an in situ growth of NiCo-LDH nanosheets by controlling ion etching and co-deposition. The obtained INPC/NiCo-LDH composite exhibited high mass capacitance (1712 F g−1 at 0.5 A g−1), good rate capability and cycling performance (86.1 % after 5000 cycles). The assembled INPC/NiCo-LDH//INPC asymmetric supercapacitor (ASC) showed excellent capacitive performance (115.9 F g−1 at 0.5 A g−1) and high energy density (41.2 Wh kg−1 at 400 W kg−1). The three prefabricated all-solid-state INPC/NiCo-LDH//INPC ASCs linked in series could successfully light up a small light bulb, showing a potential application in real life.

In situ vertically growth of 2D NiCo-BTC nanosheet arrays for binder-free flexible wearable energy storage devices

Metal-organic frameworks (MOFs) with high performance are hopeful materials for miniaturization and flexibility of energy storage devices for demands in development of modern electronic products. Thus, in this work, bimetallic MOFs composite with ultrahigh specific capacity and excellent cycling stability is acquired by a facile one-step solvothermal method. The regulated nickel‑cobalt bimetallic MOFs (NiCo-BTC) nanosheet array with the linker of 1,3,5-Benzenetricarboxylic acid (H3BTC) was in situ constructed on carbon cloth (CC), and directly served as electrode for supercapacitor without any addition of binder. Through the precisely controlled growth of NiCo-BTC nanosheets on CC, the unique composite structure allows an ultrahigh specific capacity of 644.4C g−1 at the current density of 0.5 A g−1, which is about 11.8 and 4.1 times than that of single metallic Co-BTC (54.6C g−1) and Ni-BTC (157.5C g−1), respectively. Moreover, the actually assembled flexible device based on NiCo-BTC and active carbon (AC) displays a high energy density of 32.4 Wh kg−1 (at the power density of 346 W kg−1) and an ultra-long cyclic life with a capacity retention of 91.2 % after 8000 cycles. This binder-free NiCo-BTC nanosheet electrode is also benefit for simple preparation process for flexible and all-solid supercapacitor in practical energy storage applications.

La and Fe co-doped walnut-like cubic-rhombohedral-In2O3 for highly sensitive and selective detection of acetone vapor

Cubic-rhombohedral-In2−2xLaxFexO3 (x = 0, 0.03, and 0.05) composites were prepared by a hydrothermal method. XRD and SEM reveal that pristine cubic-rhombohedral-In2O3 composite mainly consisted of In2O3 nanoparticles in the cubic phase, while introducing appropriate amount of La and Fe ions (x = 0.03 and 0.05) promoted the growth of rhombohedral-In2O3 nanosheets, which constituted the backbones of fuzzy walnut-like hierarchical structure. BET and XPS show that the La and Fe co-doped cubic-rhombohedral-In2O3 composites are higher in the BET surface area and the relative contents of surface In+ ions and OV. From the reception and conduction mechanisms, the highly sensitive and selective detection of acetone by In1.90La0.05Fe0.05O3 is attributed to the fuzzy walnut-like hierarchical structure with enhanced surface reactivity and efficient heterojunction between cubic-In2O3 and rhombohedral-In2O3.