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A covalent organic framework (ZUT-COF-SO3H) with high loading sulfonic groups was synthesized and applied in a proton conduction membrane, which has high chemical stability, high water retention, and excellent proton conduction performance.

Triazine unit functionalized covalent organic frameworks were predesigned for exceptional iodine capture through weak molecular interactions.

A metal–covalent organic framework (MCOF) catalyst with bipy pincer active sites.

A new COF with dual redox-active sites was grown on carbon nanotubes for fabricating anode material, which can provide more exposed and accessible redox-active sites and the corresponding larger capacity was achieved compared with bulk COF.

Metallic Li is considered the most promising anode material for high-energy-density batteries owing to its high theoretical capacity and low electrochemical potential. However, inhomogeneous lithium deposition and uncontrollable growth of lithium dendrites result in low lithium utilization, rapid capacity fading, and poor cycling performance. Herein, two sulfonated covalent organic frameworks (COFs) with different sulfonated group contents are synthesized as the multifunctional interlayers in lithium metal batteries. The sulfonic acid groups in the pore channels can serve as Li-anchoring sites that effectively coordinate Li ions. These periodically arranged subunits significantly guide uniform Li-ion flux distribution, guarantee smooth Li deposition, and reduce lithium dendrite formation. Consequently, these characteristics afford an excellent quasi-solid-state electrolyte with a high ionic conductivity of 1.9 × 10

Lithium (Li) metal has emerged as a promising electrode material for high-energy-density batteries. However, serious Li dendrite issues during cycling have plagued the safety and cyclability of the batteries, thus limiting the practical application of Li metal batteries. Herein, we prepare a novel metal-organic-framework-based (MOF-based) succinonitrile electrolyte, which enables homogeneous and fast Li-ion (Li+) transport for dendrite-free Li deposition. Given the appropriate aperture size of the MOF skeleton, the targeted electrolyte can allow only small-size Li+ to pass through its pores, which effectively guides uniform Li+ transport. Specially, Li ions are coordinated by the C═N of the MOF framework and the C≡N of succinonitrile, which could accelerate Li+ migration jointly. These characteristics afford an excellent quasi-solid-state electrolyte with a high ionic conductivity of 7.04 × 10-4 S cm-1 at room temperature and a superior Li+ transference number of 0.68. The Li/LiFePO4 battery with the MOF-based succinonitrile electrolyte exhibits dendrite-free Li deposition during the charge process, accompanied by a high capacity retention of 98.9% after 100 cycles at 0.1C.

Because of their large surface areas, long-range order, π-π stacking interactions and hierarchically integrated building blocks, covalent organic frameworks (COFs) have attracted increasing attention. Recently, COFs have been regarded as promising heterogeneous photocatalysts, owing to their remarkable light-harvesting and energy transition capabilities. The research progress of COFs in photocatalytic organic synthesis is summarized, such as preparation of imines through the oxidation of amines, selective oxidation of sulfides, oxidative hydroxylation of arylboronic acids, C-H bond activation, cyclization, asymmetric organic synthesis and so on. Finally, a perspective of the present challenges of photoactive COFs in organic transformations is given.

In this study, two novel fluorine-functionalized crystalline covalent organic frameworks (COFs), namely DF-TAPB-COF and DF-TATB-COF, were synthesized, and their ordered structure, porosity, suitable pore size, and abundant fluorine groups were expected to serve as effective carriers in drug delivery. The excellent cell viability of DF-TAPB-COF and DF-TATB-COF was verified using MTT assays. Both COFs exhibited very high loading capacities in terms of drug loading performance, in particular the drug loading rate of DF-TAPB-COF for 5-fluorouracil (5-FU) was up to 69%. They also exhibited efficient drug release performance in a simulated body fluid environment. Cell endocytosis experiments demonstrated that DF-TAPB-COF and DF-TATB-COF could be effectively endocytosed by cells. Hence, this study offers new insight into the design and development of COF-based drug carrier systems.

Designing materials with high triboelectric is an efficient way of improving output performance of triboelectric nanogenerators (TENGs). Herein, we synthesized a series of covalent organic frameworks (COFs) with similar skeletons but various functional groups ranging between electron-donating and electron-withdrawing. These COFs form an ideal platform for clarifying the contribution of each group to TENG performance because the pore wall is perturbed in a predesigned manner. Kelvin probe force microscopy and computational data suggest that surface potentials and electron affinities of COFs can be improved by introducing electron-donating or withdrawing groups, with the highest values observed for fluorinated COF. The TENG with fluorinated COF delivered an output voltage and current of 420 V and 64 μA, respectively, which are comparable to other reported materials. This strategy can be used to efficiently screen suitable frameworks as TENG materials with excellent output performance.

Crown ethers are a class of macrocyclic molecules with unique flexible structures but they are rarely integrated in covalent organic frameworks (COFs). To date, employing flexible organic units such as crown ethers to construct COFs with high crystallinity and surface area are still a challenge. In this work, two new COFs with different flexible crown ethers as backbone rather than side chains are synthesized and further employed for alkali metal ions separation. Both of COFs possess high surface areas, good crystallinity, and excellent chemical stability. Interestingly, these two new COFs with 18-crown-6 or 24-crown-8 units showed remarkable binding ability of K+ or Cs+ owing to the size-fit effect. This work demonstrated that the unique structural features of crown ethers will lead to increase interest in fabricating COFs with crown ethers.

With the continuous development of nuclear energy, radioactive iodine in nuclear waste is becoming increasingly harmful to the environment and human health. Herein, we synthesized two cationic covalent organic frameworks (C-TP-PDA-COFs and C-TP-BPDA-COFs) via a post-function process for an exceptional iodine capture. Compared to that of neutral COFs, the iodine uptake capacities of cationic COFs were improved 1.3 times due to electrostatic interactions between COF networks and iodine molecules. Interestingly, C-TP-BPDA-COF possessed high-density ionic units to realize a high iodine uptake value of 6.11 g g−1, which is higher than most neutral COFs and ionic porous adsorbents. This study demonstrates an effective way to construct cationic COF materials and further employ them as scaffolds for iodine capture.

Exploring covalent organic frameworks with new linkages is regarded as an efficient method to modulate the corresponding properties, and a new linkage is essential to the progress of this field. Herein, condensation of 1,3,5-triformylphloroglucinol with 1,1′-(1,4-phenylene)bis(thiourea), 1,1′-(2,5-dimethyl-1,4-phenylene)bis(thiourea) or 1,1′-(3,3′-dimethyl-[1,1′-biphenyl]-4,4′-diyl)bis(thiourea) were applied to construct COFs with thiourea linkages for the first time.

Covalent organic frameworks (COFs) have developed as a precisely tailor-made platform for integrating different functionalities into the frameworks via reticular chemistry. In this work, two COFs w...

Developing highly efficient and durable electrocatalysts for the oxygen reduction reaction (ORR) is essential for commercializing renewable and clean energy, but this remains a challenge. Herein, w...

Covalent organic frameworks (COFs) enable precise integration of various organic building blocks into porous skeletons through topology predesign. Here, we report the first example of COFs by integrating electron withdrawing bromine group onto the skeletons for triboelectric nanogenerators (TENG). The resulting framework exhibits high surface area and good crystallinity. Thus, the bromine functionalized COF has more regular aligned π columns and arrays over the skeleton than bare COFs, which in turn significantly enhances charge transport ability. As a result, bromine functionalized COFs showed higher electrical output performance at 5 Hz with a peak value of short circuit current density of 43.6 μA and output voltage of 416 V, which is 2 and 1.3 times higher than those of bare COFs (21.6 μA and 318 V), respectively. These results demonstrated that this strategy for engineering electron withdrawing groups on the skeleton could open a new aspect of COFs for developing TENG devices.

Development of porous materials combining stability and high performance has remained a challenge. This is particularly true for proton-transporting materials essential for applications in sensing, catalysis and energy conversion and storage. Here we report the topology guided synthesis of an imine-bonded (C=N) dually stable covalent organic framework to construct dense yet aligned one-dimensional nanochannels, in which the linkers induce hyperconjugation and inductive effects to stabilize the pore structure and the nitrogen sites on pore walls confine and stabilize the H3PO4 network in the channels via hydrogen-bonding interactions. The resulting materials enable proton super flow to enhance rates by 2–8 orders of magnitude compared to other analogues. Temperature profile and molecular dynamics reveal proton hopping at low activation and reorganization energies with greatly enhanced mobility., Development of porous proton-transporting materials combining stability and high performance has remained a challenge. Here, the authors report a stable covalent organic framework with excellent proton conductivity in which nitrogen sites on pore walls confine and stabilize a H3PO4 network in the channels via hydrogen-bonding interactions.

Two new covalent organic frameworks (COFs) were synthesized from 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraaniline and 2,5-dimethoxyterephthalaldehyde (Py-DMTA-COF) or 2',5'-dimethoxy-[1,1':4',1''-terphenyl]-4,4''-dicarbaldehyde (Py-DMTPDA-COF) under solvothermal conditions. These two COFs were further facilely developed as efficient photocatalytic platforms for the synthesis of thiophosphinates. Py-DMTA-COF exhibited better photocatalytic activity, broad substrate applicability, and excellent recycling capacity for the preparation of thiophosphinates from P(O)H compounds and thiols compared to Py-DMTPDA-COF. This methodology was further extended to the seamless gram-scale production of target phosphorothioate derivatives. The results demonstrate that COFs can provide a robust platform for developing metal-free, base-free, highly efficient, and reusable heterogeneous photocatalysts for organic transformations.

The development of high-efficiency and low-cost oxygen reduction electrocatalysts have become an urgent need to push fuel cells into practical application. Herein, an effective electrocatalyst Co/NC was successfully constructed, which was derived from abundant peanut shells, obtained by doping with cobalt ions and pyrolyzing in NH

Herein, we proposed a simple non-lithographic way to fabricate hierarchical Al nanopit arrays performed as deep ultraviolet (DUV, 200–300 nm) refractive index sensing. Only by adjusting the Al deposition thickness on the Al nanopit array, the hierarchical Al nanopit arrays with tunable plasmonic properties in the DUV region were obtained. The prepared hierarchical Al nanopit arrays are of very good time stability and its RI sensitivity and concentration detection limit of adenine ethanol solution reach 311 nm/RIU and 5 × 10 − 6 M , respectively, as the Al deposition thickness is 60 nm. Furthermore, the electric field distribution simulation results show that high RI sensing characteristic are mainly attributed to the local surface plasmon resonance. This investigation provides a facile way to develop low cost, high efficient and easily fabricated Al-based RI sensor in the DUV region.

The optical path difference (OPD) equations of the dual Wollaston prisms (DWP) with an adjustable air gap (AG) are derived by the wave normal tracing method, which is suitable for arbitrary incidence plane and angle. The spatial distribution of the OPD for various AG is presented. The validity of the OPD equation is verified by comparing the calculated interferograms with experimentally observed one. The performance of a novel static birefringent Fourier transform imaging spectrometer (SBFTIS) based on the DWP is investigated. The spectral resolution can be adjusted by changing the AG and the field of view can reach 10.0°, which is much larger than that predicted by our previous work. The results obtained in this article provide a theoretical basis for completely describing the optical transmission characteristic of the DWP and developing the high-performance birefringent spectral zooming imaging spectrometer.

A surface-enhanced Raman scattering (SERS)-based sandwich type immunoassay was developed for the detection of α-fetoprotein (AFP) with high sensitivity, reproducibility and selectivity. In the immunoassay, an antibody immobilized nitrocellulose (NC) membrane was employed to capture AFP and antibody conjugated silica coated gold/silver core–shell nanostars (AuNS@Ag@SiO2) were used as SERS probes. AuNS@Ag was synthesized by the direct deposition of Ag on the AuNS. The Ag shell grew outward from the center towards the tips and adopted a polyhedral shape. The AuNS@Ag nanoparticles were shown to have higher SERS activity than gold nanostars (AuNSs), and their LSPR wavelengths could be finely tuned across a wide spectrum ranging from visible to near-infrared by simply adjusting the Ag shell thickness. The silica coating improved colloidal stability of the nanostructure and provided functionality for antibody conjugation. By using 4-mercaptobenzoic acid (4-MBA) as a Raman reporter molecule, the proposed SERS sensor is able to detect AFP with a low limit of detection (LOD) of 0.72 pg mL−1 and a wide and clinically relevant linear detection range from 3 pg mL−1 to 3 μg mL−1. Hence, this SERS-based immunoassay provides a strategy for the detection of trace AFP and has potential to assist in the monitoring of prognosis for hepatocellular carcinoma (HCC) patients.

Covalent organic frameworks (COF) with periodic porous structures and tunable functionalities are a new class of crystalline polymers connected via strong covalent bonds. Constructing COF materials with high stability and porosity is attracting and essential for COFs' further functional exploration. In this work, two new covalent organic frameworks (TTA-TMTA-COF and TTA-FMTA-COF) with high surface area, large pore volume, and excellent chemical stability toward harsh conditions are designed and synthesized by integrating the methoxy functional groups into the networks. Both two COFs are further employed for iodine removal since radioactive iodine in nuclear waste has seriously threatened the natural environment and human health. TTA-TMTA-COF and TTA-FMTA-COF can capture 3.21 and 5.07 g g-1 iodine, respectively. Notably, the iodine capture capacity for iodine of TTA-FMTA-COF does not show any decline after being recycled five times. These results demonstrate both COFs possess ultrahigh capacity and excellent recyclability.

Lithography-free metal-dielectric-metal (M/D/M) configuration has attracted tremendous interest for vivid reflective color generation, especially the M/anodic aluminum oxide (AAO)/Al configuration due to its simple, cost-effective and flexible preparation processes. However, the physical mechanism of structural color generation in M/AAO/Al configuration has not been sufficiently discussed. Here, the Al/AAO/Al configurations with distinct vivid reflective colors were prepared. To reveal the color generation mechanism, the bumpy nanopore Al island film (BAlIpore) was proposed as the top meal layer. The optical properties of BAlIpore and BAlIpore/AAO/Al configurations are investigated by both experimental and finite-difference time-domain (FDTD) method. The results indicate that BAlIpore/AAO/Al configuration can generate vivid reflective colors due to the large enhancement and widening of the absorptive band in the reflective spectrum, which is the result of the strong coupling between the broadband local surface plasmon resonance (LSPR) and destructive interference (thin-film interference) supported by BAlIpore and BAlIpore/AAO/Al, respectively. Furthermore, the optical properties of the Al/AAO/Al configuration with a planar nanopore Al film (PAlpore) as the top metal layer are investigated by FDTD method and the results indicate that the PAlpore/AAO/Al configuration can’t result in vivid reflective colors because of the limit enhancement and widening of the absorptive band in the reflective spectrum, which resulted in the weak coupling between weak broadband non-resonance scattering and F-P resonance supported by the PAlpore and PAlpore/AAO/Al, respectively. The results contribute to our understanding of the vivid reflective color generation mechanism in the M/AAO/Al configuration and can be used to develop a reflective filter, color display, etc.

A new synergetic anticorrosion system was constructed via combining a self-powered cathodic protection based on triboelectric nanogenerator (TENG) and a green corrosion inhibitor of zinc gluconate (ZnG). Wind-driven TENG with a sandwich-like structure was designed, exhibiting high output performance with the peak values of short circuit current, output voltage and corresponding power reaching about 155 μA, 402 V and 13.5 mW, respectively, under a wind speed of 10 m/s. With the assistance of TENG, the migration of corrosion inhibitor can be accelerated and the formation of the protective layer becomes faster due to the driving force of electric field. The shielding effect of protective layer in turn improves the cathodic protection of TENG. The immersion experiment and electrochemical measurements including Tafel polarization curves and EIS were taken to evaluate the performance of synergetic anticorrosion system. FESEM and EDS measurements were performed to analyze the morphology and composition of the protective layer and confirm the mechanism of synergetic anticorrosion. This work expands the application of TENG in the anticorrosion field and proposes a new thought of synergetic anticorrosion method.

Covalent organic frameworks (COFs) are a novel class of crystalline porous polymers, which possessed high porosity, excellent stability, and regular nanochannels. Two-dimensional (2D) COFs provided 1D nanochannel to form the proton transport channels. The abovementioned features afforded a powerful potential platform for designing materials as proton transportation carriers. Herein, we incorporated sulfonic acid groups on the pore walls as proton sources for enhancing proton transport conductivity in the 1D channel. Interestingly, the sulfonic acid COFs (S-COFs) electrolytes with binder free exhibited excellent proton conductivity about 1.5 × 10^-2 S cm^-1 at 25 ℃ and 95% relative humidity (RH), which ranked the excellent performance in standard proton-conducting electrolytes. The S-COFs electrolytes kept the high proton conduction over the 24 h. The activation energy was estimated to be as low as 0.17 eV, which was much lower than most reported COFs. This research opens a new window to evolve great potential of structural design for COFs as the high proton-conducting electrolytes.

Covalent organic frameworks (COFs) are a new class of crystalline porous materials, maintaining porosity, stability, uniform pore channel, and well-designed skeletons. These features trait to be well suited as a platform for effective adsorption and separation of sorbents. Here, we reported microporous and stable COF with high-density N and O atoms that are implanted via the linker and vertex design. The new COF possessed high crystallinity, permanent micropores, excellent thermal and chemical stability, and high-density N and O atoms on the walls. Interestingly, the new COF is able to capture CO2 of 14.2 wt%, and iodine vapor of 456 wt%. These results evolve structural designs of COFs as effective gas uptake scaffolds.

In order to efficient photocatalytic degradation of chlorophenols by organic semiconductor perylene tetracarboxylic diimide (PTCDI), two major issues need to be addressed, namely, poor visible light utilization and easy recombination of photogenerated electrons and holes. In this work, we aimed to overcome above issues by in-situ assembling brominated-PTCDI (PTCDI-Br) on g-C3N4 forming g-C3N4/PTCDI-Br heterojunction. It showed obvious visible-light absorption enhancement by the substitution of Br. Meanwhile, Br substitution made the conduction band of PTCDI-Br closer to the valence band of g-C3N4, resulting in the reduced interface electron transfer resistance and the increased internal-electric fields from g-C3N4 to PTCDI-Br, facilitating the interfacial charge transfer. Importantly, there was an enhancement of photocatalytic activity and stability when g-C3N4/PTCDI-Br was used as the photocatalyst for degrading 4-chlorophenol (4-CP) under UV–vis light irradiation. This finding offers new insight into the design strategy for PTCDI-based photocatalysts with excellent performance.

The pre-designable porous structures found in covalent organic frameworks (COFs) render them attractive as a molecular platform for addressing environmental issues such as removal of toxic heavy metal ions from water. However, a rational structural design of COFs in this aspect has not been explored. Here we report the rational design of stable COFs for Hg(II) removal through elaborate structural design and control over skeleton, pore size, and pore walls. The resulting framework is stable under strong acid and base conditions, possesses high surface area, has large mesopores, and contains dense sulfide functional termini on the pore walls. These structural features work together in removing Hg(II) from water and achieve a benchmark system that combines capacity, efficiency, effectivity, applicability, selectivity, and reusability. These results suggest that COFs offer a powerful platform for tailor-made structural design to cope with various types of pollution.

Here we describe a general strategy based on template pyrolysis for converting conventional covalent organic frameworks into high-performance carbons, which combines conductivity, microporosity and heteroatom density, thus casting a distinct contrast to those obtained upon direct pyrolysis. The carbons serve as electrodes and exhibit exceptional performance in energy storage.

Covalent organic frameworks are designed to have backbones with different yet discrete contents of triarylamine units that interact weakly with CO2. Adsorption experiments indicate that the triarylamine units dominate the CO2 adsorption process and the CO2 uptake increases monotonically with the triarylamine content. These profound collective effects reveal a principle for designing backbones targeting for CO2 capture and separation.

Nanostructure-based localized surface plasmon resonance (LSPR) sensing have great potential for refractive index (RI) detection in the area of life science, chemical and food safety. Recently, the studies of aluminum (Al)-based nanostructures for sensing have attracted a large attention because aluminum is a cost-effective material and have excellent plasmonic characteristics from UV to near-infrared ranges. However, the fabrication of Al nanostructures used for sensing mainly focus on lithography techniques which are complex, expensive. Here, a facile method for the fabrication of hierarchical Al nanocap arrays used as LSPR sensing device was investigated. By only controlling the deposited Al thickness onto barrier layer surface of anodic aluminum oxide (AAO) template, the hierarchical Al nanocap arrays with tunable plasmonic wavelength ranging from 331 nm to 428 nm were obtained. The RI sensitivity of 80 nm hierarchical Al nanocap array is 358 nm/RIU and shows a good consistency with the FDTD simulation result. The concentration detection limit of adenine aqueous and ethanol solution are 1 × 10 − 6 M and 1 × 10 − 5 M , respectively. The results provide a new approach for developing an inexpensive, efficient, and mass-produced Al nanostructure sensor.

Aluminum nanodimple arrays (AlNDAs) formed by anodic oxidation technique have tremendous potential in synthesis of various nanostructures. Here, highly ordered AlNDAs with continuously tunable period were fabricated by one-step hard anodization (HA) aluminum in a mono-concentration sulfuric/oxalic acid mixed electrolyte ( 0.3 M/0.3 M ). We found that ordered AlNDAs were obtained at anodization voltage range of 30 to 50 V. By controlling anodization voltage and total charge density, the AlNDAs with period of 60–89 nm were obtained. The results provide an effective approach for precisely regulating the period of smaller period AlNDAs.

A series of two-dimensional covalent organic frameworks (2D COFs) locked with intralayer hydrogen-bonding (H-bonding) interactions were synthesized. The H-bonding interaction sites were located on the edge units of the imine-linked tetragonal porphyrin COFs, and the contents of the H-bonding sites in the COFs were synthetically tuned using a three-component condensation system. The intralayer H-bonding interactions suppress the torsion of the edge units and lock the tetragonal sheets in a planar conformation. This planarization enhances the interlayer interactions and triggers extended π-cloud delocalization over the 2D sheets. Upon AA stacking, the resulting COFs with layered 2D sheets amplify these effects and strongly affect the physical properties of the material, including improving their crystallinity, enhancing their porosity, increasing their light-harvesting capability, reducing their band gap, and enhancing their photocatalytic activity toward the generation of singlet oxygen. These remarkable effects on the structure and properties of the material were observed for both freebase and metalloporphyin COFs. These results imply that exploration of supramolecular ensembles would open a new approach to the structural and functional design of COFs.

Covalent organic frameworks are a class of crystalline porous polymers that integrate molecular building blocks into periodic structures and are usually synthesized using two-component [1+1] condensation systems comprised of one knot and one linker. Here we report a general strategy based on multiple-component [1+2] and [1+3] condensation systems that enable the use of one knot and two or three linker units for the synthesis of hexagonal and tetragonal multiple-component covalent organic frameworks. Unlike two-component systems, multiple-component covalent organic frameworks feature asymmetric tiling of organic units into anisotropic skeletons and unusually shaped pores. This strategy not only expands the structural complexity of skeletons and pores but also greatly enhances their structural diversity. This synthetic platform is also widely applicable to multiple-component electron donor–acceptor systems, which lead to electronic properties that are not simply linear summations of those of the conventional [1+1] counterparts., Covalent organic frameworks are crystalline porous polymers integrating molecular building blocks into periodic structures. Here, the authors report a general multiple-component condensation strategy that enables the use of one knot and two or three linkers to synthesize complex, anisotropic frameworks.

We proposed a rapid, simple and room-temperature method to fabricate hierarchical silver nanocap arrays, in which hot spots could be facilely engineered on three-dimensional curved surface. Both optical property and surface-enhanced Raman scattering (SERS) activity displayed non-monotonic Ag thickness dependence. Furthermore, the simulation results obtained by finite-difference time-domain (FDTD) method reveal that hot spots intensity and density on three-dimensional curved surface significantly vary and strongly depend on deposited Ag thickness. The investigation opens a possibility for facile fabrication of SERS substrate with promising hot spot engineering on three-dimensional surface and extremely high SERS activity.

Polyoxins and nikkomycins are potent antifungal peptidyl nucleoside antibiotics, which inhibit fungal cell wall biosynthesis. They consist of a nucleoside core and one or two independent peptidyl moieties attached to the core at different sites. Making mutations and introducing heterologous genes into an industrial Streptomyces aureochromogenes polyoxin producer, resulted in the production of four polyoxin-nikkomycin hybrid antibiotics designated as polyoxin N and nikkoxin B-D, whose structures were confirmed using high resolution MS and NMR. Two of the hybrid antibiotics, polyoxin N and nikkoxin D, were significantly more potent against some human or plant fungal pathogens than their parents. The data provides an example for rational generation of novel peptidyl nucleoside antibiotics in an industrial producer.

Two types of highly Raman-enhancing arrays substrates were fabricated using anodic aluminum oxide (AAO) templates by controlling the AAO template temperature and evaporated silver thickness during e-beam evaporating: complex patterned Ag nanoparticle arrays abundant in sub-5 nm gaps (type I); hexagonal Ag nanopore arrays (type II). The surface enhanced Raman scattering (SERS) enhancement factors (EF) of both substrates are estimated experimentally to exceed 10 5 , especially that of type I reaches 10 7 due to the existence of numerous sub-5 nm gaps. The simulation using finite-difference time-domain (FDTD) method confirmed that gap effect has significantly improved the substrates’ SERS activity.