Semiconductor-based Materials Research Articles

A review of electrospun metal oxide semiconductor-based photocatalysts.

In recent years, photocatalytic materials with a nanofiber-like morphology have garnered a surge of academic attention due to their distinctive properties, including an expansive specific surface area, a considerable high aspect ratio, a pronounced resistance to agglomeration, superior electron survivability, and robust surface activity. Consequently, the synthesis of photocatalytic nanofiber materials through various methodologies has drawn considerable attention. The electrospinning technique has been established as a prevalent method for fabricating nanofiber-structured materials, owing to its advantageous properties, including the ability for mass production and the assurance of high continuity. This review focuses on metal oxide semiconductor-based materials, which are crucial components of photocatalysts. We summarize several recent studies that explore morphology modulation, surface modification, element doping, and composite construction using uniaxial and coaxial electrospinning techniques. Finally, we present potential approaches for constructing high-activity photocatalytic systems through electrospinning technique.

Metal-Free Peptide Semiconductor-Enhanced Raman Scattering.

There is a growing demand for sustainable and safe materials in developing technological systems and devices, including those that enhance Raman scattering. Organic (bio) materials based on simple peptides are one class of such materials. This study investigates self-assembled semiconducting peptides as metal-free substrates for surface-enhanced Raman scattering. Our results reveal significant variations in Raman enhancement factors, spanning up to 2 orders of magnitude. We examined specific Raman enhancement selection rules related to the energy levels and structural configurations of the probe molecules. The effectiveness of these rules underscores the importance of strong molecule-peptide coupling and efficient charge transfer for achieving optimal Raman enhancement factors. These insights offer a foundational understanding of peptide-molecule interactions and the underlying chemical mechanisms driving Raman enhancement, highlighting the potential of organic semiconductor-based materials as highly effective platforms for enhancing Raman scattering in chemical sensing applications.

A Protocol for Unveiling the Nature of Photocatalytic Hydrogen Evolution Reactions: True Water Splitting or Sacrificial Reagent Acceptorless Dehydrogenation?

Photocatalytic water splitting for hydrogen evolution is a highly topical subject in academic research and a promising approach for sustainable fuel production from solar energy. Due to the mismatched energy diagram of the photosensitizer (especially semiconductor-based materials where band-edge engineering is not trivial) and the redox potential of the half-reactions of water splitting, photocatalytic H2 generation from water splitting is usually accelerated by the addition of hole scavengers, i.e. sacrificial reagents such as alcohols, amines, and thiols. However, the source of the protons of the evolved H2 is often neglected, and it is questionable whether such systems are really water splitting. Here, we discuss recent reports on sacrificial reagent-assisted photocatalytic water splitting and present our recent findings, which showcase that the sacrificial reagent in the investigated photocatalytic water splitting systems inherently undergoes acceptorless dehydrogenation, with H2O serving as the proton shuttle, the amount of which doesn't change during the course of the reaction.

Catalytic methanol cracking to hydrogen and formaldehyde over heterogeneous catalysts by radiolysis: Sectoral industrial symbiosis by waste radiation utilisation

In order to create a sustainable, carbon-neutral society, it is of utmost importance to link the energy sector with the chemical industry. Radiation from nuclear power plants proves to be useful for H2 production from water or carriers such as methanol. In our study, we investigated the potential for the production of hydrogen and formaldehyde by endothermic radiolytic cracking of 50 mol% aqueous methanol, which can be produced by direct CO2 hydrogenation without distillation. We developed an elegant experimental setup and performed irradiation tests in the TRIGA reactor with system analysis by GC-MS (gas chromatography with mass spectroscopy), SEM-EDS (scanning electron microscopy with energy dispersive spectroscopy), XRD (X-ray powder diffraction) and Monte Carlo simulations of radiation absorption. Among the different routes tested, a semiconductor-based photocatalytic material (TiO2) increased the H2 yield by 24%. In the critical evaluation of radiation utilisation, spent fuel radiation sources were found to be promising as they require low heat exchange and could produce 3600 kg H2/day in a single spent fuel pool. The advantage of radiolytic methanol cracking lies in its ability to produce formaldehyde and hydrogen (∼53% methanol value increase), whereas conventional partial oxidation of methanol with O2 for formaldehyde production (only ∼31% methanol value increase) inevitably produces water, which reduces the overall energy efficiency.

Effect of morphology on the optical limiting of BiVO4 films

Precise control over the morphology and crystal structure of semiconductor-based optical materials is essential for optimizing their nonlinear optical properties. Morphological factors significantly affect the material’s interaction with light, influencing nonlinear absorption, harmonic generation, and optical confinement. In this study, the nonlinear optical (NLO) properties and optical limiting (OL) performance of bismuth vanadate (BiVO4) films depending on precursor solution pH condition, powder morphology and weight percentage of the BiVO4 powders in PMMA (10–30 wt.%) were investigated. The BiVO4 powders were synthesized via the hydrothermal method and the effect of precursor solution pH (pH of 1, 7.5 and 12) was investigated on the size and morphology of the BiVO4 powders. BiVO4 films were prepared using the spin coating method utilizing the BiVO4 powders and PMMA. The bandgap values of films were found to change from 3.39 to 3.56 eV depending on the BiVO4 growth solution pH. The nonlinear absorption coefficients (βeff), saturation intensity thresholds (ISAT) and optical limiting (OL) threshold were obtained using the open aperture (OA) Z-scan experiment. It has been observed that the nonlinear absorption and optical limitation performance of the BiVO4 films can be altered by changing the powder morphology and BiVO4 weight concentration. BiVO4 thin films fabricated using a precursor solution pH 12 and weight concentration of 30 wt.% showed the best performance among all fabricated films with the highest nonlinear absorption coefficient (βeff), saturation density threshold (ISAT) and lowest OL threshold value.

Emerging 2D nanoscale metal oxide sensor: semiconducting CeO2nano-sheets for enhanced formaldehyde vapor sensing.

Herein, we fabricated nanoscale 2D CeO2sheet structure to develop a stable resistive gas sensor for detection of low concentration (ppm) level formaldehyde vapors. The fabricated CeO2nanosheets (NSs) showed an optical band gap of 3.53 eV and cubic fluorite crystal structure with enriched defect states. The formation of 2D NSs with well crystalline phases is clearly observed from high-resolution transmission electron microscope (HRTEM) images. The NSs have been shown tremendous blue-green emission related to large oxygen defects. A VOC sensing device based on fabricated two-dimensional NSs has been developed for the sensing of different VOCs. The device showed better sensing for formaldehyde compared with other VOCs (2-propanol, methanol, ethanol, and toluene). The response was found to be 4.35, with the response and recovery time of 71 s and 310 s, respectively. The device showed an increment of the recovery time (71 s to 100 s) with the decrement of the formaldehyde ppm (100 ppm to 20 ppm). Theoretical fittings provided the detection limit of formaldehyde ≈8.86 ± 0.45 ppm with sensitivity of 0.56 ± 0.05 ppm-1. The sensor device showed good reproducibility with excellent stability over the study period of 135 d, with a deviation of 1.8% for 100 ppm formaldehyde. The average size of the NSs (≈24 nm) calculated from HRTEM observation showed lower value than the calculated Debye length (≈44 nm) of the charge accumulation during VOCs sensing. Different defect states, interstitial and surface states in the CeO2NSs as observed from the Raman spectrum and emission spectrum are responsible for the formaldehyde sensing. This work offers an insight into 2D semiconductor-based oxide material for highly sensitive and stable formaldehyde sensors.

Additive Manufacturing: A Paradigm Shift in Revolutionizing Catalysis with 3D Printed Photocatalysts and Electrocatalysts Toward Environmental Sustainability.

Semiconductor-based materials utilized in photocatalysts and electrocatalysts present a sophisticated solution for efficient solar energy utilization and bias control, a field extensively explored for its potential in sustainable energy and environmental management. Recently, 3D printing has emerged as a transformative technology, offering rapid, cost-efficient, and highly customizable approaches to designing photocatalysts and electrocatalysts with precise structural control and tailored substrates. The adaptability and precision of printing facilitate seamless integration, loading, and blending of diverse photo(electro)catalytic materials during the printing process, significantly reducing material loss compared to traditional methods. Despite the evident advantages of 3D printing, a comprehensive compendium delineating its application in the realm of photocatalysis and electrocatalysis is conspicuously absent. This paper initiates by delving into the fundamental principles and mechanisms underpinning photocatalysts electrocatalysts and 3D printing. Subsequently, an exhaustive overview of the latest 3D printing techniques, underscoring their pivotal role in shaping the landscape of photocatalysts and electrocatalysts for energy and environmental applications. Furthermore, the paper examines various methodologies for seamlessly incorporating catalysts into 3D printed substrates, elucidating the consequential effects of catalyst deposition on catalytic properties. Finally, the paper thoroughly discusses the challenges that necessitate focused attention and resolution for future advancements in this domain.

Synthesis, characterization and application of ternary composite of CdS/MoS2/reduced graphene oxide for photocatalytic degradation of sunset dye

Environmental impacts, energy applications, photocatalysis on semiconductor-based hybrid materials has drawn a lot of interest recently. Having a gap in between 1 and 2 eV, the Transition Metal Dichalcogenide (TMDSc) group of materials can be good option for a two-dimensional material. A straightforward microwave synthesis technique was used for synthesizing CdS/MoS2/rGO ternary composite SEM images and XRD analysis revealed the presence of CdS/MoS2/rGO in the nanocomposite particles. The crystal structure of CdS and MoS2 is hexagonal. In terms of wavelength, the greatest absorption peak of CdS is 514 nm, and its bandwidth is 2.42 eV, whereas MoS2 band width is between 1.8 - 1.9 eV. The size of CdS is 1 nm and MoS2 is 500 nm. The average size of the nanocomposite was 1 nm. In the present work the photocatalytic activity of sunset yellow dye is checked by ternary composite nanoparticles of CdS under visible light irradiation. The photocatalytic activity is determined by various factors like effect of catalyst in which amount of catalyst varies, effect of different pH, variation in the conc. of dye and the effect of different temp. As the time interval rises by 180 min from 10 min, the dye's degradation efficiency enhances from 33% to 95%.

Fabrication of 2D graphene oxide incorporating S-scheme Sn2S3–In2S3 heterojunctions for enhanced photocatalytic mineralization of organic pollutants

Harnessing solar energy using semiconductor-based materials to generate charge pairs to effectively drive photo-redox reactions has been envisioned as a promising approach toward a sustainable future.

Recent advances in green synthesis of diluted magnetic plasmonic-based semiconductor nanomaterials for biomedical applications

The green synthesis of nanoparticles (NPs) is of utmost importance in nanoscience due to its eco-friendly and sustainable approach. This approach reduces chemical usage, energy consumption, and waste generation. Our featured article presents an elaborate account of green synthesis, and various biomedical applications of diluted magnetic semiconductor-based and plasmonic-based semiconductor material, particularly focusing on zinc oxide and titanium dioxide NPs. We assertively review the necessity of an environment-friendly, cost-effective, easy-to-handle, smart, and easy approach for synthesizing ZnO and TiO2 NPs and their applications. Both ZnO and TiO2 NPs got a lot of attention because of their unique chemical, physical and biological properties. Moreover, plasmonic based diluted magnetic semi-conductor possess additional advantages in terms of their band gaps and visible light absorbance compared to bared nanoparticles. These distinct properties make them exceptionally useful in biomedical fields such as antibacterial, antimicrobial, anticancer, antifungal, and cytotoxicity. We provide various green routes for synthesizing ZnO and TiO2 NPs, along with pictorial demonstrations. Additionally, we assertively review the antibacterial capacity of both ZnO and TiO2 NPs and their mechanisms in detail in this featured review.

Biomass encapsulated ZIF-8-derived ZnO carbon aerogels for efficient uranium extraction by synergistic adsorption-photoreduction

Semiconductor-based photocatalytic materials have been widely used in photoreduction uranium systems. However, semiconductor-based materials still have some problems such as difficult recovery, few adsorption sites, poor stability, and large bandgap width. Based on this, we constructed 3D porous konjac glucomannan-derived carbon-encapsulated carbon-doped ZnO carbon aerogels (KC@C-ZnO-X) for U(VI) adsorption-photoreduction based on the gelling properties of Konjac glucomannan (KGM) and the unique structure of ZIF-8. The KC@C-ZnO-1.5 achieved the U(VI) removal rate of 93.5 % in 200 mg/L U(VI) solution and greatly weakened the photocorrosion of ZnO. And then the KC@C-ZnO-1.5 continued to maintain an outstanding U(VI) removal rate of 92.9 % after five cycles. Further characterization tests found that the role of 3D KGM-derived carbon aerogel (KC) encapsulation improves the stability of ZnO and carbon doping reduces the band gap width of ZnO. The mechanistic study showed that KC as the “skeleton” encapsulating C-ZnO not only enabled the catalyst to be recycled but also enhanced the photostability of ZnO. The synergistic effect of the C-ZnO and KC promoted photogenerated charge separation and facilitated the generation of ·O2−, leading to the further formation of the stable (UO3·NH3·H2O) crystalline phase.

Chemically Engineered Sulfur Vacancies on Few-Layered Molybdenum Disulfide Nanosheets for Remarkable Surface-Enhanced Raman Scattering Activity

In recent years, molybdenum disulfide nanosheets (MoS2 NSs) with sulfur surface defects have been used for surface-enhanced Raman scattering (SERS). However, methods to generate sulfur defects on the MoS2 NS surface are sophisticated and expensive. In this study, we present a relatively straightforward approach to quickly creating sulfur defects on MoS2 NSs by chemical treatment with NaBH4. Few-layered MoS2 NSs (FL-MoS2 NSs) were formed by exfoliating bulk-MoS2 in isopropanol. By oxidation–reduction reactions of FL-MoS2 NSs mixed with a suitable concentration of NaBH4, the resulting MoS2 NSs with abundant sulfur defects (SV-FL-MoS2 NSs) can be obtained. Spectroscopic and electron microscopic methods are used to demonstrate sulfur defects in SV-FL-MoS2 NSs. Rhodamine (R6G) and rhodamine-B (RhB) were used as Raman analytes to evaluate the SERS efficiency of SV-FL-MoS2 NSs. The developed SERS substrate provided detection limits of 1 × 10–8 M for both R6G and RhB, with enhancement factors of 2.21 × 106 and 4.02 × 106, respectively. Our measurements of SV-FL-MoS2 NSs’ energy band gap and R6G/RhB confirmed that charge transfer (CT) and tight molecular contacts are responsible for their excellent SERS sensitivity. With the development of new, low-cost semiconductor-based SERS materials, this discovery could impact materials science and biosensing platforms.

TiO2-CeO2 assisted heterostructures for photocatalytic mitigation of environmental pollutants: A comprehensive study on band gap engineering and mechanistic aspects

Industrial pollution is a substantial problem in the growing world of continuous innovative products and intensive developments. Pollution due to organic contaminants is the major detrimental components to environmental cleanness and sustainability. The textile industries alone produce about 1.3 million various dyes and pigments that absorb and reflect sunlight in water. This process highly affects the photosynthetic cycle of algae and other living organisms, thus balancing natural ecosystem. The breakdown of organic pollutants into harmful products, which are mutagenic, carcinogenic, and toxic to living organisms, creates a serious environmental concern globally. Nevertheless, recently application of heterogeneous photocatalysis in facilitating the removal of these organic effluents is very attractive and efficient, using various semiconductor-based composite materials which act as catalysts under light irradiation. This review focuses on recent developments of TiO2-CeO2 based nanostructure semiconductor materials, which include structural and interfacial ameliorations such as doping with other metals, non-metals, metal oxides and carbonaceous materials. Both TiO2 and CeO2 are highly redox and exchangeable (Ti+4/Ti+3 and Ce+4/Ce+3), and their performance is boasted by their associated defects and oxygen vacancy structure properties, making them amenable to high photoactivity performances. Herein, the effect of various synthesis factors on structural, electronic, optical, and morphological properties, and thus on modification of band gap edges, as well as on their photocatalytic activity and applications, is also reviewed.

Molecular Specificity in the Intense Surface-Enhanced Raman Scattering on Copper(II) 8-Hydroxyquinoline Microcrystals

π-Conjugated microcrystals of metal complexes are extensively used in catalysis, sensing, and as biomedicine. However, their application as surface-enhanced Raman spectroscopy (SERS) substrates is unexplored. SERS substrates with the ease of tailoring and that provide molecule-specific enhancement are desirable for the selective detection of diverse species. Nonetheless, the rational design of such SERS substrates is difficult for conventional metal and semiconductor-based materials. We show that π-conjugated copper 8-hydroxyquinolinate (CQ) microcrystals exhibit molecular specificity in SERS enhancement. CQ microcrystals show unprecedented Raman signal enhancements up to 28,372 ± 1953 for the probe molecule rhodamine-6G, 13,407 ± 1969 for rhodamine B, and 12,816 ± 900 for the copper(II)–picolinate complex at 785 nm laser excitation. Experiments also revealed that the Raman signal enhancements of binary mixtures over CQ microcrystals could be analyte-specific. Computational analyses demonstrate that π-electron-rich CQ microcrystals are highly electron-dense, and band structure calculations show that they possess metallic properties along all crystallographic axes. The combination of metallicity and high electron density in a metal complex microcrystal resulted in unique features such as good analyte selectivity and efficient SERS activity.

Enhanced Photocatalytic Degradation Activity Using the V2O5/RGO Composite.

Semiconductor-based photocatalyst materials played an important role in the degradation of organic compounds in recent years. Photocatalysis is a simple, cost-effective, and environmentally friendly process for degrading organic compounds. In this work, vanadium pentoxide (V2O5) and V2O5/RGO (reduced graphene oxide) composite were synthesized by a hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Raman spectroscopy, and UV-Vis spectroscopic analysis, etc. Raman analysis shows the occurrence of RGO characteristic peaks in the composite and different vibrational modes of V2O5. The band gap of flake-shaped V2O5 is reduced and its light absorption capacity is enhanced by making its composite with RGO. The photocatalytic degradation of methylene blue (MB) was studied using both V2O5 and V2O5/RGO composite photocatalyst materials. The V2O5/RGO composite exhibits a superior photocatalytic performance to V2O5. Both catalyst and light play an important role in the degradation process.

Interfacial coupled engineering of plasmonic amorphous MoO3-x nanodots/g-C3N4 nanosheets for photocatalytic water splitting and photothermal conversion

Semiconductor-based plasmonic materials have attracted extensive attention for photocatalytic systems. However, their photocatalytic reactions are hindered by limited light-harvesting ability and the transfer rate of photo-generated electrons. Herein, vacancy engineering and phase engineering are rationally integrated to develop amorphous molybdenum oxide (a-MoO3−x) nanodots anchored on g-C3N4 as a highly active photocatalyst. Through high localized surface plasmon resonance (LSPR) effect of a-MoO3−x nanodots and tunable electrical properties induced by the heterostructural interface, the Z-scheme a-MoO3−x/g-C3N4 heterostructure demonstrates broadband absorption and the excited photo-generated electrons. Further theoretical calculations demonstrate that the enhancement of photocatalytic and photothermal performance is mainly attributed to the highly localized Anderson tail states of a-MoO3−x. Consequently, the a-MoO3−x/g-C3N4 heterostructure exhibits a photocurrent density of ∼36.5 μA cm−2, which is about 2.7 and 4.1 times higher than that of pure g-C3N4 nanosheets (∼13.5 μA cm−2) and a-MoO3−x nanodots (∼9 μA cm−2), respectively. The photocatalytic performance enhancement relying on defects and long-range disorder of a-MoO3−x in Z-scheme heterostructure is explored.

Recent Developments in Heterogeneous Photocatalysts with Near-Infrared Response

Photocatalytic technology has been considered as an efficient protocol to drive chemical reactions in a sustainable and green way. With the assistance of semiconductor-based materials, heterogeneous photocatalysis converts solar energy directly into chemical energy that can be readily stored. It has been employed in several fields including CO2 reduction, H2O splitting, and organic synthesis. Given that near-infrared (NIR) light occupies 47% of sunlight, photocatalytic systems with a NIR response are gaining more and more attention. To enhance the solar-to-chemical conversion efficiency, precise regulation of the symmetric/asymmetric nanostructures and band structures of NIR-response photocatalysts is indispensable. Under the irradiation of NIR light, the symmetric nano-morphologies (e.g., rod-like core-shell shape), asymmetric electronic structures (e.g., defect levels in band gap) and asymmetric heterojunctions (e.g., PN junctions, semiconductor-metal or semiconductor-dye composites) of designed photocatalytic systems play key roles in promoting the light absorption, the separation of electron/hole pairs, the transport of charge carriers to the surface, or the rate of surface photocatalytic reactions. This review will comprehensively analyze the four main synthesis protocols for the fabrication of NIR-response photocatalysts with improved reaction performance. The design methods involve bandgap engineering for the direct utilization of NIR photoenergy, the up-conversion of NIR light into ultraviolet/visible light, and the photothermal effect by converting NIR photons into local heat. Additionally, challenges and perspectives for the further development of heterogeneous photocatalysts with NIR response are also discussed based on their potential applications.

Visible Light-Responsive CeO2/MoS2 Composite for Photocatalytic Hydrogen Production

Semiconductor-based photocatalyst materials play an important role in solar hydrogen production. In the present work, we achieved the successful synthesis of a CeO2/MoS2 composite using a facile hydrothermal method. For the preparation of the CeO2/MoS2 composite, the hydrothermal process was carried out at a temperature of 120 °C for 24 h, and its performance in hydrogen production was tested. The CeO2/MoS2 composite was characterized using XRD, XPS, Raman spectroscopy, SEM, and optical investigation. The optical study showed that after forming a composite with MoS2, the absorption edge of CeO2 is shifted from the ultraviolet to the visible light region. Bandgap values decreased from 2.93 for CeO2 to 2.34 eV for the CeO2/MoS2 composite. In photocatalytic hydrogen production, Na2SO3–Na2S was used as a sacrificial agent. The CeO2/MoS2 composite exhibited superior photocatalytic hydrogen production performance compared to CeO2 and MoS2. The CeO2/MoS2 composite achieved higher charge separation efficiency, faster charge transfer, more active sites available for redox reactions, and greater affinity towards the reactant ions due to such properties its hydrogen evolution rate has reached 112.5 μmol/h. The photostability of the CeO2/MoS2 composite was tested in up to four cycles, with each cycle being four hours.

Photothermal-Effect-Enhanced Photoelectrochemical Water Splitting in MXene-Nanosheet-Modified ZnO Nanorod Arrays

Engineering semiconductor photoelectrodes with excellent photogenerated charge separation and transportation capabilities is of great practical interest for efficient photoelectrochemical (PEC) water splitting. Herein, MXene nanosheets as a bifunctional surface modifier were grafted onto ZnO nanorod arrays for enhanced PEC water oxidation performance. As a hole transfer material, the MXene nanosheets combine with ZnO nanorods to construct a heterojunction for restraining the recombination of photogenerated charges and boosting charge separation. Furthermore, as a photothermal material, the MXene nanosheets can produce a lot of heat for elevating the surface temperature of photoanodes in situ under extra near-infrared (NIR) irradiation, thus accelerating the charge transfer and improving the oxygen evolution reaction kinetics. As a result, the photocurrent density, durability, bulk charge separation, and surface charge injection efficiency of the ZnO/MXene-NIR photoanode outperform significantly those of pure ZnO photoanodes. This proof-of-concept work may shed light on the development of advanced semiconductor-based composite materials with the synergy of the photoelectric and photothermal effects for solar energy conversion.

Fluorescent Covalent Organic Frameworks: A Promising Material Platform for Explosive Sensing.

Covalent organic frameworks (COFs) are a novel class of porous crystalline organic materials with organic small molecule units connected by strong covalent bonds and extending in two- or three-dimension in an ordered mode. The tunability, porosity, and crystallinity have endowed covalent organic frameworks the capability of multi-faceted functionality. Introduction of fluorophores into their backbones or side-chains creates emissive covalent organic frameworks. Compared with common fluorescent organic solid materials, COFs possess several intrinsic advantages being as a type of irreplaceable fluorescence materials mainly because its highly developed pore structures can accommodate various types of guest analytes by specific or non-specific chemical bonding and non-bonding interaction. Developments in fluorescent COFs have provided opportunities to enhance sensing performance. Moreover, due to its inherent rigidified structures and fixed conformations, the intramolecular rotation, vibration, and motion occurred in common organic small molecules, and organic solid systems can be greatly inhibited. This inhibition decreases the decay of excited-state energy as heat and blocks the non-radiative quenching channel. Thus, fluorescent COFs can be designed, synthesized, and precisely tuned to exhibit optimal luminescence properties in comparison with common homogeneous dissolved organic small molecule dyes and can even compete with the currently mainstream organic solid semiconductor-based luminescence materials. This mini-review discusses the major design principle and the state-of-the-art paragon examples of fluorescent COFs and their typical applications in the detection and monitoring of some key explosive chemicals by fluorescence analysis. The challenges and the future direction of fluorescent COFs are also covered in detail in the concluding section.