Fabrication Of Heterojunction Research Articles

Synthesis of magnetic layered double hydroxide (Fe3O4@CuCr-LDH) decorated with ZIF-8 for efficient sonocatalytic degradation of tetracycline

A series of Fe3O4@CuCr-LDH hybrids decorated with different amount of ZIF-8 (FLZ, 10–40 wt%) was prepared using simple methods and characterized with different techniques. The activity of the synthesized nanocomposites was investigated in the sonocatalytic degradation of tetracycline (TC) antibiotic from wastewater. When the content of ZIF-8 in the nanocomposite structure was 20 wt%, the FLZ-20 sonocatalyst exhibited the high performance in the sonocatalytic removal of TC. At optimum conditions (0.7 g/L catalyst dosage, pH of 7, 50 mg/L initial concentration of antibiotic, and 15 min sonication time) of the sonocatalytic removal of TC approached to 91.4% under ultrasonic irradiation (USI) using FLZ-20. This efficiency was much higher than those of obtained results by Fe3O4@CuCr-LDH and pristine ZIF-8. The formed ●OH and ●O2− exhibited the major roles in the sonocatalytic TC degradation process. The excellent performance of FLZ-20 can be attributed to the heterojunctions created between composite components, which could improve the electron transfer ability and effectively separate e−/h+ pairs. In addition, FLZ-20 showed the superior reusability and stability during three successive recycling. Moreover, the facile magnetically separation of the sonocatalyst from the aqueous solution was another outstanding feature, which prevents the formation of secondary pollutants. It can be concluded that the fabrication of heterojunctions is an efficient procedure to promote the sonocatalytic acting of the catalyst.

Harnessing the Potential of Cube-like Holmium doped Bismuth Niobate (Ho-Bi5Nb3O15) amalgamated with rGO Sheets for Rapid Photocatalytic Elimination of Crystal Violet and Acetylsalicylic Acid

Synthesis of unique morphologies in photocatalytic materials, coupled with utilization of wide-spectrum solar energy through rare earth doping, holds significant promise to maximize the potential of photocatalysts. Herein in, cube-like Holmium (Ho) doped Bi5Nb3O15 was synthesized by the hydrothermal method and integrated with reduced graphene oxide (rGO) sheets. As synthesized Ho-Bi5Nb3O15@rGO composite along its analogs i.e., Bi5Nb3O15 and Ho-Bi5Nb3O15 was characterized by XRD, SEM, FT-IR, TGA, I-V, EIS, Mott-Schottky and photo-current measurements. Phase studies showed that crystallite size for Bi5Nb3O15, Ho-Bi5Nb3O15, and Ho-Bi5Nb3O15@rGO was 27.4, 25.5, and 13.5 nm, respectively. Optical analysis exhibited a reduction in the band gap in consequent to Ho doping from 2.54 to 2.19 eV for Ho-Bi5Nb3O15. Conductivity and photo-current measurements showed a remarkable increase in both electrical conductivity and photo-response of Ho-Bi5Nb3O15 upon its incorporation into rGO matrix, reaching maximum values of 1.72 × 10-2 S/m and 0.66 μA, respectively. The enhanced photocatalytic activity of Ho-Bi5Nb3O15@rGO was ensured through the outstanding photo-degradation efficiency (96.5%) against crystal violet (CV), greater than Bi5Nb3O15 (49%) and Ho-Bi5Nb3O15 (63.4%). Additionally, Ho-Bi5Nb3O15@rGO showed sufficient potential towards the degradation of acetylsalicylic acid (ASA) with 79.1% photo-degradation. This elevated photocatalytic activity of Ho-Bi5Nb3O15@rGO is believed to be contributed by the collaborative outcomes aroused from the Ho-doping and heterojunction fabrication among cubical Ho-Bi5Nb3O15 and rGO sheets. Hence, our work proposes an efficient strategy for the development of innovative photolytic materials for sustainable wastewater remediation.

Rational fabrication of Z-scheme heterojunction ZnFe2O4-seed@TpTt-COF for the visible-light-driven photocatalytic degradation of bisphenol A in food waste leachate boosted by primitive humic acid

Herein, we proposed a method by pre-embedding organic covalent organic framework TpTt-COF(TpTt) (consisting of the electron donor 1,3,5-triazine-2,4,6-triamine (Tt) and electron acceptor 2,4,6-triformylphloroglucinol (Tp) aldehyde) within inorganic ZnFe2O4 core to serve as seed for the in-situ grafting of organic TpTt shell tightly. The as-formed ZnFe2O4-seed@TpTt-COF (Z-S@TpTt) core–shell structure exhibited visible-light-driven photocatalytic degradation of BPA effectively. This may stem from the rationally tuned energy band structure of ZnFe2O4-seed via TpTt pre-anchoring, thus enabled a Z-scheme electron transfer way within the heterojunction to broaden the light adsorption, accelerate the charge transfer and maintain their thermodynamic redox capacity. More strikingly, humic acid (HA) in the actual wastewater (food waste leachate (FWL), where BPA highly frequently presented) could even boost the photocatalytic degradation of BPA. Comprehensive characterizations and DFT calculations revealed that HA acts as a critical “electron shuttle” to further promote the separation of electron-hole pairs via the formation of an EDA complex with the Z-S@TpTt. The gathered electrons on CB of ZnFe2O4-seed and holes on VB of TpTt may generate more •O2– and 1O2, thus the improved performance of Z-S@TpTt core–shell heterojunction in BPA degradation was achieved. Besides the promoted catalytical activity, the convenient separation ability and extraordinary chemical/thermal stability inherited from the magnetic core and the COF shell also enabled robust reuse of Z-S@TpTt heterojunction in FWL. All of these properties endowed Z-S@TpTt heterojunction with the practical application potential to remove BPA in an economical and environment-friendly way, which is also compatible with the “waste control by waste” strategy today.

Fabrication of WO3-Ag3PO4 heterojunction on carbon cloth for efficient visible-light degradation of rhodamine B

The WO3-Ag3PO4 heterojunction on carbon cloth (CC@WO3-Ag3PO4) was prepared through a facile two step approach. The photocatalysts are evaluated in the degradation of rhodamine B (RhB) under visible light irradiation; CC@WO3-Ag3PO4 exhibited enhanced photocatalytic RhB efficiency. The calculated k for the degradation of RhB over CC@WO3@Ag3PO4 is 0.03097 min−1, which is higher than those for reactions over CC@Ag3PO4 (0.01254 min−1) and CC@WO3 (0.00935 min−1). The photocatalytic efficiency is significantly enhanced after formation of the CC@WO3-Ag3PO4 heterojunction. This could be mainly attributed to improved photogenerated electron-hole pairs separation ability after formation of the CC@WO3-Ag3PO4 heterojunction. Furthermore, the carbon cloth serving as support for photocatalyst can enhance the contact area of the photocatalyst with RhB solution and visible light due to its large specific surface area. Additionally, CC@WO3-Ag3PO4 photocatalyst can be quickly and completely recycled, effectively avoiding recontamination.

Fabrication of Z-scheme heterojunctions of CDs@WO3/g-C3N4 nanocomposite photocatalyst with enhanced visible-light photocatalytic degradation of malachite green

Fabrication of Z-scheme heterojunctions of CDs@WO3/g-C3N4 nanocomposite photocatalyst with enhanced visible-light photocatalytic degradation of malachite green

Insights into the solar-light activated adsorption-photocatalysis of ZnLaxBi2−xO4 heterojunctions for tetracycline hydrochloride removal

Metal oxides-based heterojunction fabrication is a promising strategy to eliminate antibiotics from wastewater via adsorption-photocatalysis. ZnLaxBi2−xO4 hybrids with various La/Bi molar ratios were fabricated for enhancing the adsorption-photocatalytic elimination of tetracycline hydrochloride (TCH). Oxygen-defected ZnLaxBi2−xO4 composites provided the sufficient sites for photon capture and pollutants adsorption. In addition, the tight p-n-p type interface among oxygen-defected La2O3, ZnO, and spinel ZnBi2O4 favored the rapid transfer and migration of photo-excited e-/h+ pairs, enlarging the visible light utilization. Hence, ZnLaxBi2−xO4 samples had the better adsorption-photocatalytic activity than ZnLa2O4 and ZnBi2O4 for TCH removal. Langmuir and second-order models well described the adsorption isotherms and kinetics of ZnLaxBi2−xO4 samples, respectively. The adsorption capacity of optimal ZnLa1.75Bi0.25O4 with a La/Bi molar ratio of 7:1 was 406.85 mg g−1, and its removal efficiency of 210 mg L−1 TCH solution was 98.04 % within 150 min. The change in valence states of surface compositions induced to the declined removal efficiency of ZnLa1.75Bi0.25O4 to 91.95 % after five cycle times.

Fabrication of multi-component heterojunction Ag/AgCl/g-C3N4/Sn-In3O2 for enhanced degradation of RhB under visible light

High-efficiency visible-light photocatalysts have been recognized as a cost-effective approach for the degradation of organic pollutants in wastewater. In this study, we constructed a novel multi-component heterojunction photocatalyst Ag/AgCl/g-C3N4/Sn-In2O3 through a simple thermal polymerization and photo-assisted reduction processes. The photocatalytic activity of Ag/AgCl/g-C3N4/Sn-In2O3 was remarkably improved compared to other samples in the degradation of Rhodamine B (RhB). The degradation of RhB by 5 % Ag/AgCl/g-C3N4/Sn-In2O3 reached 98.5 % within 60 min, while the degradation rates under g-C3N4, g-C3N4/Sn-In2O3, and Ag/AgCl/g-C3N4 were found to be 41.8 %, 73.6 %, and 85.9 %, respectively. Electron spin resonance (ESR) signals trapping and radical scavenging confirmed that the h+ and ·O2− were the two main reactive species in photodegradation RhB. The result provides innovative insights that could inform the future design and development of photocatalysts with exceptional efficiency.

Erratum to: Fabrication of MXene-Bi2WO6 heterojunction by Bi2Ti2O7 hinge for extraordinary LED-light-driven photocatalytic performance

Erratum to: Fabrication of MXene-Bi2WO6 heterojunction by Bi2Ti2O7 hinge for extraordinary LED-light-driven photocatalytic performance

Interface engineered 2D-2D-g-C3N4/SnWO4 S-scheme heterojunction: Clioquinol degradation and dopamine sensing properties

A convenient and walkable protocol has been established to simplify the fabrication of surface-engineered heterojunctions between 2D/2D g-C3N4-β-SnWO4. The method involves a one-step, simultaneous thermal exfoliation-deposition technique that utilizes bulk carbon nitride and stannous tungstate in a thermal spreading process. The prepared catalysts demonstrate excellent performance in the photocatalytic decomposition of Clioquinol (a neurotoxic drug) and dopamine sensing. The results indicate that the optimal loading of carbon nitride is 12 %, with this catalyst completely decomposing clioquinol within 80 min. Lower and higher loadings result in inferior performance due to ineffective interfacial contact, the formation of a bulk-like carbon nitride phase, and the encapsulation of stannous tungstate particles, respectively. A plausible mechanism has been proposed based on scavenger studies. The 12 % g-C3N4-SnWO4 sample exhibits the lowest charge transfer resistance and demonstrates good dopamine sensing properties. The selective sensing performance has been confirmed in the presence of glucose, ascorbic acid, and urea. The limit of detection (LOD) for the 12 % g-C3N4-SnWO4 sensor system is determined to be 1.78 μM.

Fabrication of MXene-Bi2WO6 heterojunction by Bi2Ti2O7 hinge for extraordinary LED-light-driven photocatalytic performance

Fabrication of MXene-Bi2WO6 heterojunction by Bi2Ti2O7 hinge for extraordinary LED-light-driven photocatalytic performance

A novel carbon doped CeO2/g-C3N4 heterostructure for disinfection of microorganisms and degradation of Malachite green and Amoxicillin under sunlight

The fabrication of semiconductor heterojunction with defect engineering is an efficient technique to boost photocatalytic activity. In this study, a novel step-scheme heterojunction C-CeO2/g-C3N4 nanocomposite was developed via the hydrothermal method for the degradation of aqueous dye and antibiotics in sunlight. The photocatalytic experiment of the CeO2/g-C3N4 heterojunction nanocomposite reveals superior photocatalytic activity and significant reusability. Further, 91.9 % of Malachite green (MG) and 87.5 % of Amoxicillin(AMX) were degraded by C-CeO2/g-C3N4 nanocomposite under 150 mins of sunlight irradiation, which is ∼ 1.78 folds of the photodegradation performance of C-CeO2. The decomposition of MG and AMX into non-toxic secondary compounds was verified by total organic carbon and high-performance liquid chromatography analysis. Further, the migration and separation of charge carriers due to photons were confirmed through electrochemical analysis and, photoluminescence spectroscopy. The potential S-Scheme charge transfer pathway for improved photocatalytic activity was postulated via the quenching experiment, Mott Schottky (M-S) plot, and XPS Valance band spectroscopy (VB-XPS). In addition, the C-CeO2/g-C3N4 nanocomposite displays excellent bactericidal and fungicidal activity against pathogenic microorganisms S. aureus, E. coli, and C. albican. Hence, the synthesized S-Scheme heterojunction C-CeO2/g-C3N4 nanocomposite is an ideal catalyst for the detoxification of industrial wastewater.

Dual-functional, highly efficient CaIn2S4/PDA@SnO2 photocatalyst with Z-Scheme for photocatalytic hydrogen production from water splitting and organic pollutant degradation

Heterojunction can be used to develop semiconductor catalysts with high photocatalytic activity. In this work, a Z-Scheme CaIn2S4(CIS)/PDA@SnO2 photocatalyst was successfully synthesized. Firstly, SnO2 hollow nanospheres were prepared by hydrothermal method. On this basis, SnO2 hollow nanospheres wrapped by polydopamine (PDA) were obtained via self-polymerization of dopamine. Finally, the CIS/PDA@SnO2 composites were synthesized via a one-step oil bath method. The heterojunction has successfully achieved effective separation of electron-hole pairs. PDA acted as a photosensitizer and an electron transfer medium in the heterojunction. Multiple characterization techniques such as XRD, SEM, TEM, BET, XPS, PL, UV–vis DRS, EPR and photoelectrochemical measurements were used for material structure and performance analysis. The photocatalytic performance of the photocatalysts was tested by photocatalytic hydrogen production from water splitting and RhB solution degradation. A flower-like close contact between CaIn2S4 and PDA@SnO2 interfaces can be obviously observed via SEM and TEM images. The band gap energies (Eg) of CaIn2S4 and PDA@SnO2 are 2.06 eV and 3.74 eV. CaIn2S4/PDA@SnO2-1(CPS-1) exhibits stronger light absorption together with lower transfer resistance compared to other samples. CPS-1 showed excellent photocatalytic hydrogen production and RhB degradation performance. Furthermore, the results of active species capture experiments, Mott-Schottky curve, XPS measurement and other tests show that it is logical to use the Z-Scheme charge mobility process to explain the better photocatalytic activity of the CIS/PDA@SnO2 composite. This work will present an efficient option for the fabrication of Z-Scheme heterojunctions and possibly further develop a new avenue for the control of the structure of semiconductor photocatalysts.

Interfacial Engineering of Cobalt Thiophosphate with Strain Effect and Modulated Electron Structure for Boosting Electrocatalytic Hydrogen Evolution Reaction

AbstractThe fabrication of heterojunctions is an intriguing approach to boost the reactivity of catalysts. However, facile preparation of desirable heterojunction materials remains a challenge. Here, novel CoPS3/CoS2 heterojunctions are created by an intuitive phosphatization process on the basis of structurally flexible cobalt sulfide precursors. Significant stress effect exists at these heterogeneous interfaces, resulting in lattice distortions and the exposure of more active sites. The interface interaction also modifies the catalyst's electronic structure to improve its electrical conductivity and hydrogen adsorption capabilities. Notably, the overpotential of the CoPS3/CoS2 heterojunction for electrocatalytic hydrogen evolution reaction is just 36.3 mV, which is far superior to those of single‐component catalysts and competitive with comparable catalysts reported. This work not only offers an innovative electrocatalyst but also a strategy that can be used to create heterojunctions based on related transition metal thiophosphates.

In Situ Rapid Fabrication of Graphene-Copper Heterojunctions Using Fiber Laser Direct Writing.

Multifunctional three-dimensional heterostructures for flexible electronics have gained significant attention due to their distinctive structural formability and superior electronic and optoelectronic properties. Nevertheless, conventional fabrication techniques have yet to be optimized for flexible substrates. In this study, a straightforward fiber laser direct writing (FLDW) process is demonstrated for the simultaneous fabrication of diodes (PN junctions) and bipolar junction transistors (BJTs) on flexible polyimide substrates, which is realized through the deposition of multifunctional p- or n-type copper oxide films (CuOx) and p- or n-type porous laser-reduced graphene oxide films (LrGO) using fiber laser ablation and deposition. The presence of both p- and n-type semiconductor films is confirmed through material characterization. The fabricated PN junctions exhibit reasonable diode rectification ratios, ranging from 20 to 220, and perform reliably under numerous operating conditions such as light-dark illumination and elevated temperatures. Furthermore, I-V curve analysis indicates that the current gain and electrical performance of printed negative-positive-negative (NPN) (or positive-negative-positive, PNP) BJTs can be tailored by adjusting the laser energy density of the FLDW process and the base gap width of the BJTs. As a proof of concept, the FLDW process is successfully employed to deposit both NPN (or PNP) BJTs composed of LrGO/CuOx heterostructures with controlled current gains. Its ease of operation, versatility, and cost-effectiveness make FLDW promising for large-scale flexible electronics fabrication.

Photocatalysis of silicon nanowires decorated with metallic nanoparticles and graphene oxide under different light intensities

This work shows silicon nanowires (SiNWs), decorated with different nanoparticles, as a photocatalytic material under different lighting conditions. In this system, the comparison between different materials and the influence of light intensity on their performances are studied. On the other hand, the synthesis of SiNWs was done by a metal-assisted chemical etching. The decoration with nanoparticles of copper CuNPs and cuprous oxide CuO2NPs was conducted with the electroless technique. Graphene oxide (GO) lamellar particles passing through an atmospheric pressure plasma (APPJ) were instantaneously ionized losing OH radicals and connecting them into a continuous coating around the SiNWs nanostructures. Such a layer with a large contact area among SiNWs/GO/Cu/CuO2 was obtained with a small thickness of about 10–20 nm. This is proposed to allow and increase charge carrier transference to the aqueous solution for redox reactions to degrade the dye molecules. Through statistical analysis, we compared the percentages of the decrease in methyl orange concentration used to measure the photocatalytic performance. SiNWs – CuNPs surfaces, in combination with high-intensity light, exhibit higher degradation percentages and rate constants. The graphene oxide coatings were deposited on monocrystalline silicon wafers and silicon nanowires, constituting a semiconductor-semiconductor heterojunction. This is an innovation proposed in this work that could lead to the fabrication of semiconductor heterojunctions with Z-scheme complementarity.

Facile synthesis of defect induced CeO2/MIL-53(Fe) nanocatalyst: Strategically switching the charge transfer dynamics for remarkable enhancement of photocatalytic Bisphenol A degradation and H2 evolution

This work reports the fabrication of heterojunction between defect induced CeO2 and iron based metal organic framework (MIL-53). A simple chemical redox etching methodology was adopted to narrow the band gap of pristine CeO2 through oxygen vacancy engineering. The photocatalytic efficacy of defect induced CeO2/MIL-53 (MCO-X) heterojunction was studied in Bisphenol A (BPA) breakdown and photocatalytic hydrogen generation from water splitting. The significantly improved photocatalytic application of MCO-X heterojunction could be attributed to the switching of charge dynamics mechanism from Type-1 to Type-II due to defect formation in the pristine CeO2. The optimal photocatalyst (MCO-30) displayed the highest photocatalytic BPA degradation with rate constant (0.045 min−1) and H2 evolution (3286.2 μmol.h−1. g−1) respectively. This study provides a comprehensive analysis on how defect in pristine CeO2 in MCO-X heterojunction can switch the charge transfer mechanism from Type-1 to Type-II to achieve remarkable visible light harnessing capacity and photocatalytic activity.

A comprehensive review on tailoring factors of porous bismuth oxyhalide photocatalysts for wastewater treatment application

BackgroundPhotocatalysis is a green, environmentally friendly approach for converting organic contaminants into harmless byproducts. Especially, Bismuth oxyhalides (BiOX, where X = Cl, Br and I) have emerged as promising photocatalysts for wastewater treatment due to their layered-by-layered structure, strong chemical stability and nontoxicity in compare to other metal oxides, which makes the photocatalyst advantageous for photocatalytic application. MethodsThis review provides an overview of recent developments in the synthesis and application of BiOX-based porous photocatalysts for the removal of organic contaminants from wastewater. Firstly, morphology-controlled synthesis of BiOX in degradation of organic contaminants. Then, modulation of electronic structure through doping, facet engineering and surface engineering has been highlighted for better photocatalytic applications. Furthermore, fabrication of diverse heterojunctions and co-catalyst loading upon BiOX are introduced, which can vary photocatalytic activity towards the degradation of organic contaminants. Significant findingsFinally, this review ended on the future trend and prospects of BiOX for the creation of potential high-performance photocatalysts in the near future. The porous structure of BiOX improved photocatalytic activity, pollutant degradation efficiency, visible light response charge carrier separation, and stability. Overall, bismuth oxyhalide photocatalysts have a lot of potential for effective and long-term wastewater treatment, and their development represents an important step towards addressing the global water pollution crisis.

Photocatalytic degradation of tetracycline using surface defective black TiO2–ZnO heterojunction photocatalyst under visible light

Fabrication of heterojunction and surface defective engineering, through the formation of oxygen vacancies, are among the various photocatalytic enhancement techniques. A combination of these techniques has the prospect of enhancing photocatalytic activities through improved light absorption capabilities and charge separation process of the photocatalysts. In this study, a heterojunction of black titanium oxide-zinc oxide (BTiO2–ZnO) nanocomposite was synthesized using the conventional sol-gel approach, coupled with aluminum foil-assisted NaBH4 reduction. The structure, morphology, surface properties, and optical characteristics of the synthesized material were studied using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV–vis absorption spectra, scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscope (TEM). The XRD confirmed the successful formation of BTiO2–ZnO heterostructure, while SEM revealed the structural morphology as pseudo-spherical with slight agglomeration. BTiO2–ZnO was found to be more efficient than BTiO2 and BZnO for the removal of tetracycline with degradation efficiencies of 63, 58, and 56 % respectively. The effects of process parameters such as the amount of photocatalyst, pollutant's concentration, and the initial solution pH on photocatalytic degradation study were systematically explored. The results confirm that the formation of the heterostructure from BTiO2 and BZnO could offer a facile route to improving the catalytic degradation of tetracycline. Therefore, this study offers a novel perspective on the design of efficient metal oxide photocatalyst systems that rely on the integration of defect engineering and heterojunction for the removal of organic contaminants.

Novel and facile strategy for immobilization of Ag3PW12 crystals on graphitic carbon nitride (g-C3-N4) sheets, a superior photocatalyst for decomposition of organic waste

The high electron-holes recombination rate in pure graphitic carbon nitride (C3–N4) restrict their photocatalytic efficiency. In this research work, we successfully immobilized Ag3PW12O40 a polyoxometalate-base crystal on graphitic carbon nitride 2D sheet through physical grinding method to prevent charges recombination on the surface. Both the materials were prepared separately and then grinded after mixing, to get C3–N4@Ag3PW12 heterojunction. The prepared C3–N4@Ag3PW12 composites were tested with different characterization techniques to confirm its structural integrity and successful fabrication of heterojunction. The composite catalyst showed expansion in UV light absorbance where it promotes from 406 nm to 454 nm for pure C3–N4 and composite C3–N4@Ag3PW12-30 % respectively. The composite showed better electron-holes separation, confirmed from its electrochemical performance such as TPC (total photocurrent) and PL data. The prepared catalysts were tested for the degradation of two types of organic dyes such as methylene blue and Rhodamine B under photoirradiation. The C3–N4@Ag3PW12-30 % composite photocatalyst showed efficient photocatalytic activity and removed 99 % methylene blue in 75 min while removed 99.4 % Rhodamine B in 60 min while the pure Ag3PW12 and C3–N4 could only remove 26.3 % and 37.7 % methylen blue and 43.54 % and 53.38 % rhodamin B respectively, in the same conditions. The results show that, the Ag3PW12 crystals deposition on C3–N4 2D sheets is a preferred approach to enhance the catalytic performance of C3–N4 2D sheet.

Liquid‐Phase Transfer of Organic–Inorganic Halide Perovskite Films for TEM Investigation and Planar Heterojunction Fabrication

AbstractOrganic–inorganic halide perovskites (OIHPs) show high promise in optical and electronic applications such as solar cells, light‐emitting diodes, and nonlinear optics. However, the fundamental knowledge of the atomic‐scale microstructures in OIHP thin films is limited due to the challenge in characterizing them using transmission electron microscopy (TEM). Here a solution‐phase “release‐and‐transfer” method is demonstrated, which entails the lifting of OIHP films from their original substrates while maintaining the film integrity, followed by a sequential transfer onto a TEM grid. The freestanding nature of the OIHP films with a nanoscale thickness, prepared as such, allows a direct TEM observation in the plan view, complementing those typical cross‐sectional views enabled by focus‐ion‐beam specimen fabrication. Using low‐dose scanning TEM, the atomic‐scale microstructure of transferred OIHP films is confirmed to be generally maintained, while the microstrain existing in original films is largely relaxed. This “release‐and‐transfer” method is generic to both standard 3D and low‐dimensional OIHPs. Based on a simple layer‐by‐layer transfer, the fabrication of a 2D–3D planar heterojunction with a good interfacial contact and optoelectronic properties is achieved. This unique methodology offers new opportunities to accelerate the fundamental and practical developments of OIHP materials and devices.