Surface Of ZnO Nanorods Research Articles

Excellent NO2 sensor based on porous Pd-ZnO nanorods prepared by a facile hydrothermal method

Noble metal nanoparticles (NPs) decorated on the surface of semiconducting metal oxides to enhance the gas-sensitive properties of sensing materials have attracted considerable interest from numerous researchers worldwide. Here, we introduce an effective method to decorate Pd NPs on the surface of porous ZnO nanorods to improve NO2 gas-sensing performance. Porous ZnO nanorods were synthesized using a simple hydrothermal method without surfactant. Surface decoration of porous ZnO nanorods with Pd NPs was performed through in situ reduction of PdCl2 using Pluronic as the reducing agent. The gas-sensing properties of porous Pd-ZnO nanorods were evaluated toward NO2 toxic gas in a concentration range of 0.1–2 ppm at various operating temperatures of 25 °C–250 °C. Pd NPs decorated on the surface of porous ZnO nanorods not only improve the sensor response (3-folds) and reproducibility but also reduce the optimal operating temperature. The improvement in gas-sensing activity is attributed to the modulation of the depletion layer via oxygen adsorption and the formation of the Schottky potential barrier between Pd and ZnO through chemical and electronic mechanisms.

Facile and precise synthesis of core-shell ZnO/C nanorods with excellent microwave absorption

Carbonaceous materials have great prospects in microwave absorption due to their lightweight and corrosion resistance. However, their high conductivity leads to poor impedance matching, posing a significant challenge for obtaining outstanding microwave absorption (MA) materials from carbonaceous materials. In this work, the core-shell ZnO/C nanorods (ZCNs) are prepared by covering conductive carbon on the surface of ZnO nanorods through a simple stirring process in ambient temperature and calcination treatment. The thickness of carbon shell is carefully regulated to realize appropriate impedance matching and strong microwave dissipation capability. ZCN with 30.2 nm of carbon shell achieves outstanding microwave absorption in low frequency and broadband microwave absorption because of the synergies of optimized impedance matching and enhanced dielectric loss: the reflection loss of 49.9 dB at 6.32 GHz, and the effective absorption bandwidth of 6.4 GHz at a corresponding thickness of 2.0 mm. RCS simulation results have verified its excellent performance in practical application. This study proposes a simple and effective idea for the efficient utilization of carbonaceous materials in microwave absorption.

Electric field emission properties of ZnO/microcrystalline diamond composite structures modified by Cu nanoparticles decoration

ZnO nanorods hold promise as cathode materials for field electron emission (FEE) applications, yet their high work function and wide bandgap can hinder performance. Recent research has focused on utilizing Cu nanoparticles (NPs) to decorate and modify the FEE properties of these nanorods, leveraging Cu's low work function and excellent conductivity. In this study, ZnO nanorods were synthesized on diamond substrates via the sol method to create ZnO/microcrystalline diamond (MCD) composite structures. Subsequently, Cu NPs were decorated onto the nanorods using a gel method. The influence of Cu NP concentration on the organization and FEE performance of the composites was investigated. The decorated of Cu NPs can improve the Fermi energy level of the nanorods, replenish electrons lost on the surface due to oxygen adsorption, and improve the field emission performance. With the increase of doping concentration, Cu NPs increase, and when the doping concentration is 0.5 M, NPs appear agglomeration phenomenon, resulting in that the surface of ZnO nanorods is almost completely covered by bulk Cu NPs, and the field emission performance decreases. The minimum value of the turn-on electric field is 0.48 V/μm and the maximum value of the current density is 1.60 mA/cm2, when the decorated concentration is 0.25 M.

Molecularly imprinted polymer-based extended-gate field-effect transistor chemosensors for selective determination of antiepileptic drug.

Ultrathin molecularly imprinted polymer (MIP) films were deposited on the surfaces of ZnO nanorods (ZNRs) and nanosheets (ZNSs) by electropolymerization to afford extended-gate field-effect transistor sensors for detecting phenytoin (PHT) in plasma. Molecular imprinting efficiency was optimized by controlling the contents of functional monomers and the template in the precursor solution. PHT sensing was performed in plasma solutions with various concentrations by monitoring the drain current as a function of drain voltage under an applied gate voltage of 1.5V. The reliability and reproducibility of the fabricated sensors were evaluated through a solution treatment process for complete PHT removal and PHT adsorption-removal cycling, while selectivity was examined by analyzing responses to chemicals with structures analogous to that of PHT. Compared withthe ZNS/extracted-MIP sensor and sensors with non-imprinted polymer (NIP) films, the ZNR/extracted-MIP sensor showed superior responses to PHT-containing plasma due to selective PHT adsorption, achieving an imprinting factor of 4.23, detection limit of 12.9ng/mL, quantitation limit of 53.0ng/mL, and selectivity coefficients of 3-4 (against tramadol) and ~ 5 (against diphenhydramine). Therefore, we believe that the MIP-based ZNR sensing platform is promising for the practical detection of PHT and other drugs and evaluation of their proper dosages.

Ag-modified enhance the performances of ZnO@CFs based omnidirectional photoelectrochemical ultraviolet detectors

There are several prospective applications for omnidirectional ultraviolet (UV) detectors and underwater detection detectors in optical systems and optical fields. In this work, ZnO nanorods arrays were grown on carbon fibers (CFs). An appropriate amount of Ag nanoparticles (NPs) was deposited on the surface of ZnO nanorods by photochemical deposition. This improved the performance of photoelectrochemical (PEC) based UV detectors. Under 365 nm and 10 mW cm−2 UV irradiation, the photocurrent density of the 30s-Ag/ZnO@CFs based PEC UV detector can reach 1.28 mA cm−2, which is about 7 times that of the ZnO@CFs based PEC UV detector, and the rising time is shortened from 0.17 to 0.10 s. The reason is that increased absorption of ultraviolet light induced by the localized surface plasmon resonance. In addition, the detector exhibits a good flexibility and remains flexible after hundreds of bends and twists. Moreover, the detector is responsive in the range of rotation angle from 0° to 360°. It provides an insight to improve the photoelectric performance and underwater omnidirectional detection ability of the PEC UV detector.

0D/1D CuO-Cu2O/ZnO p-n heterojunction with high photocatalytic activity for the degradation of dyes and Naproxen

The development of highly active photocatalysts with broad spectrum response is of paramount importance for photocatalytic applications. Herein, heterostructured CuO-Cu2O/ZnO photocatalysts were prepared in a single step and under mild conditions using a photodeposition process which allows to deposit CuO-Cu2O particles with an average size of ca. 2.4 nm on the surface of ZnO nanorods. The p-n heterojunction built between CuO-Cu2O and ZnO allows to increase both the visible light response of the photocatalyst and the charge separation. The CuO-Cu2O(10%)/ZnO catalyst exhibits the highest activity for the degradation of dyes (Rhodamine B and Remazol Brilliant Blue R) and of Naproxen under simulated solar light irradiation. Based on scavenging experiments, holes, superoxide radicals O2●- and singlet oxygen 1O2 are the dominant species involved in the photocatalytic degradation and a mechanism is proposed. Due to its high stability and photocatalytic performance in various water matrices, the CuO-Cu2O(10%)/ZnO nanohybrid is of high potential for the large scale remediation of organic pollutants in wastewater.

Superior visible-light absorbing Ag@ZnO nanorods hybrid photocatalyst for efficient decomposition of commercial pharmaceuticals tetracycline and amoxicillin

This work assesses the role of the noble metal silver in the visible-light sensitization of UV-active ZnO by introducing a localized plasmonic resonance effect and enhancing the spatial charge carrier separation. We herein synthesize ZnO nanorods via a solvothermal approach, yielding nanorods of length and diameter 1.356 ± 0.619 μm and 120.56 ± 25.09 nm, respectively. Silver nanoparticles are reduced on the surface of ZnO nanorods via the photodeposition route. XRD spectra reveal a high crystallinity and wurtzite-type structure for ZnO with new peaks for cubic phase Ag upon Ag-loading. The diffraction peaks shift upon Ag modification, indicating partial incorporation of Ag into the ZnO lattice. Further, upon Ag-decoration, a slight increase in dislocation density and micro strain is obtained, which could suppress the recombination rate of charge carriers. The DRS spectra reveal a band gap contraction of materials from 3.19 to 2.98 eV with increasing Ag density. The PL spectra confirmed that the optimum Ag concentration of 3 wt% is proficient in harvesting visible light towards high photocatalytic degradation efficiencies of tetracycline (92.1 %) and amoxicillin (76.4 %) in 90 min as compared to 49.4 % and 38 % over pristine ZnO nanorods. TOC studies reveal only partial mineralization of ∼42.7 % (tetracycline) and ∼31.3 % (amoxicillin) due to the formation of reaction intermediates identified by HR-MS chromatograms. In addition, degradation pathways are proposed through the fragments at different m/z ratios.

Construction of a ZnO Heterogeneous Structure Using Co3O4 as a Co-Catalyst to Enhance Photoelectrochemical Performance.

Recently, heterostructured photocatalysts have gained significant attention in the field of photocatalysis due to their superior properties compared to single photocatalysts. One of the key advantages of heterostructured photocatalysts is their ability to enhance charge separation and broaden the absorption spectrum, thereby improving photocatalytic efficiency. Zinc oxide is a widely used n-type semiconductor with a proper photoelectrochemical activity. In this study, zinc oxide nanorod arrays were synthesized, and then the surfaces of ZnO nanorods were modified with the p-type semiconductor Co3O4 to create a p-n junction heterostructure. A significant increase in the photocurrent for the ZnO/Co3O4 composite, of 4.3 times, was found compared to pure ZnO. The dependence of the photocurrent on the morphology of the ZnO/Co3O4 composite allows for optimization of the morphology of the ZnO nanorod array to achieve improved photoelectrochemical performance. The results showed that the ZnO/Co3O4 heterostructure exhibited a photocurrent density of 3.46 mA/cm2, while bare ZnO demonstrated a photocurrent density of 0.8 mA/cm2 at 1.23 V. The results of this study provide a better understanding of the mechanism of charge separation and transfer in the heterostructural ZnO/Co3O4 photocatalytic system. Furthermore, the results will be useful for the design and optimization of photocatalytic systems for water splitting and other applications.

Construction of hierarchical ZnO-NiCo2O4-NiCo2O4 core-shell microstructure with efficient microwave absorption

Core-shell structural design is an attractive strategy to achieve high-performance microwave absorbers. Nevertheless, it still remains a problem to simultaneously obtain superior microwave dissipation and impedance matching for microwave absorption (MA) materials. In this work, ZnO-NiCo2O4-NiCo2O4 (ZNN) core–shell microstructure is designed and fabricated by covering NiCo2O4 nanosheets on the surface of ZnO nanorod and next growth of NiCo2O4 nanoparticles. With the synergies from the NiCo2O4 nanosheets improving the microwave attenuation capability and the NiCo2O4 nanoparticles increasing the impedance matching, ZNN possesses efficient MA performance: the strongest reflection loss is −59.93 dB at the corresponding thickness of 2.6 mm, and the maximum absorption bandwidth is 7.04 GHz at 2.4 mm, which covers the entire Ku-band. RCS simulation also indicates that ZNN has outstanding MA performance. Moreover, this study proposes a point for the utilization of nickel–cobalt oxides in MA materials, and offers a reference for the design of core–shell structural absorbers.

Effect of UV-O3 treatment on the performance of UV detector based on zinc oxide/molybdenum disulfide nanosheet heterostructures

UV photodetectors based on ZnO nanostructures, using a metal-semiconductor-metal (MSM) configuration, are popular due to their simple fabrication. However, they experience high dark currents and slow photoresponse speeds. This is due to a high recombination rate for photogenerated electrons and holes as well as low charge carrier mobility attributable to ZnO's inherent defects. In this study, MoS2 nanosheets was employed to cover the surface of ZnO nanorods, creating a unique architecture that focuses the impact of MoS2 solely on light absorption and charge transfer on the ZnO surface. Subsequently, a 15-min UV-O3 exposure is applied to the ZnO/MoS2 structure. The ZnO/MoS2UVo heterostructure exhibits remarkable results, including a six-fold increase in sensitivity compared to pure ZnO, Additionally, the Detectivity increases by 265 %, while the Responsivity and Quantum Efficiency rise by up to 102 %. These enhancements are attributed to the reduction of dark current coming from the reduction of oxygen vacancies as sulfur edge atoms from MoS2 fill these vacancies. Furthermore, additional dark current reduction post UV-O3 treatment is due to both the reduced ZnO oxygen vacancies and the formation of a thin MoO3 passivation layer on the ZnO NR surface. Despite these achievements, the study acknowledges the presence of multiple junctions between ZnO, MoS2, and MoO3, which still pose challenges for efficient charge transfer to the electrodes.

Synergetic enhancement effect of two-dimensional MoS2 nanosheets and metal organic framework-derived porous ZnO nanorods for photodegradation performance.

Two-dimensional transition metal dichalcogenides and semiconductor metal oxides have shown great potential in photocatalysis. However, their stability and efficiency need to be further improved. In this paper, porous ZnO nanorods with high specific surface area were prepared from metal-organic framework ZIF-8 by a simple hydrothermal method. A MoS2/ZnO composite was constructed by loading MoS2 onto the surface of porous ZnO nanorods. Compared with ZnO materials prepared by other methods, MoS2/ZnO prepared in this paper exhibits superior photocatalytic performance. The enhanced photocatalytic activity of the MoS2/ZnO composite can be attributed to the formation of heterojunctions and strong interaction between them, which greatly facilitate the separation of electrons and holes at the contact interface. In addition, due to the wide absorption region of the visible spectrum, MoS2 can greatly broaden the light absorption range of the material after the formation of the composite material, increase the utilization rate of visible light, and reduce the combination of electrons and holes. This study provides a new way to prepare cheap and efficient photocatalysts.

Zinc oxide nanorods electronically controlled terahertz modulator

AbstractMetal oxides are commonly employed in terahertz (THz) modulator devices operating in the THz frequency band. These metal oxides, which rely on electronic control, exhibit a clear response to THz waves. The modulation of THz waves is achieved by applying an electric field directly onto the surface of ZnO nanorods and their metal dopants. This external electric field has the capability to modulate both the phase and transmittance of the THz wave. The devices based on Au‐doped ZnO nanorods demonstrate a significant enhancement in modulation depth due to the incorporation of the localized surface plasmon effect. In the realm of active THz modulation, the velocity of electric modulation is enhanced while the required driving power is reduced. The primary focus of this research article is to present an analysis of the active modulation properties and the underlying principles of ZnO nanorods and their metallic dopants when subjected to an applied electric field. The modulation bandwidth range from 0.1 to 1.0 THz for our devices. The phase modulation of 0.866 rad and the transmittance modulation with the modulation depth of 0.4 was realized.

Metal-organic gel derived ZnO/α-Fe2O3 heterostructures for sensitive NO2 detection

Fabrication of metal oxide semiconductor heterostructures is an important means to improve sensor performance. However, the design of efficient heterostructures to reduce the operating temperature of metal oxides and obtain high sensitivity and selectivity remains a challenge. In this work, ZnO/α-Fe2O3 heterostructures were prepared by pyrolysis of Fe-based organic gel on ZnO nanorods, and their NO2 sensing properties were systematically studied. The α-Fe2O3 nanoparticles transformed from Fe-organic gel are evenly dispersed on the surface of ZnO nanorods, endowing the materials with a large specific surface area and remarkable charge modulation at the ZnO/α-Fe2O3 interface. The ZnO/α-Fe2O3 sensor shows superior selectivity and repeatability for NO2 detection at 175 °C, as well as short response-recovery time (24/32 s), low detection limit (79 ppb) and reliable stability. This study provides a useful strategy for the construction of core-shell heterostructure sensing materials.

Polypyrrole-decorated ZnO/g-C3N4 S-scheme photocatalyst for rhodamine B dye degradation: Mechanism and antibacterial activity

Polypyrrole (PPy) and graphitic carbon nitride (g-C3N4) nanoparticles are added to the surface of ZnO nanorods to successfully produce a Step-scheme (S-scheme) photocatalytic system known as g-C3N4/PPy/ZnO (GPZ) by a multistep process: hydrothermal and calcination processes, followed by polymerization. During the formation of the heterojunction, the oxygen vacancy (OV) on ZnO promotes effective separation and increases the redox power of the photogenerated excitons via the built-in internal electric field of S-scheme pathways between g-C3N4 and ZnO. The successful construction of the S-scheme heterojunction was substantiated through X-ray photoelectron spectroscopy, experimental calculations, radical trapping experiment, and liquid electron spin resonance (ESR) characterization, whereas the existence of OVs was well confirmed by ESR analysis. Meanwhile, the PPy served as a supporter, and the polaron and bipolaron species of PPy acted as electron and hole acceptors, respectively, which further enhances the charge-carrier transmission and separation in the ternary GPZ photocatalyst. The photocatalytic activity of the PPy-designed ternary photocatalyst g-C3N4/PPy/ZnO is outstanding and is greater than that of other samples like g-C3N4, ZnO, and ZnO/g-C3N4 and remove 99.0% of RhB (50 mg/L) in 60 min. RhB could be degraded most effectively by GPZ-0.75 photocatalysis at a pH of 7, and 1.0 g/L of the photocatalyst was the ideal concentration. Gram-positive (G + ve) and Gram-negative (G-ve) microorganisms were used as test subjects to determine the antibacterial effectiveness of the photocatalysts using the good diffusion approach. Ternary g-C3N4/PPy/ZnO heterostructure outperformed its competitors in terms of antibacterial activity. Additionally, after five cycles, the as-synthesized photocatalyst showed superb stability. By using a photocatalyst with a superior utilization efficiency of visible light energy, this paper offers a clearly promising, highly effective, and simple method to destroy exceedingly harmful and renowned contaminants.

Novel ZnO/BiOI nanorod photoanode with interface p-n heterojunction and excellent photoelectric conversion efficiency for photocathodic protection of stainless steel

Bismuth oxyhalide nanoheterojunctions with high photovoltaic conversion efficiency by constructing internal electric field have received extensive attention for photocathode protection (PCP) applications. In this work, BiOI/ZnO nanorod composites (BiOI/ZnO NRs) were synthesized by spin coating and hydrothermal method. The BiOI nanoparticles were found uniformly anchored on the surface of hexagonal wurtzite ZnO nanorods. Morphology and Mott Schottky plots analysis confirm the structure of the p-n heterojunctions at the interface of BiOI and ZnO. Loading of BiOI on the ZnO surface results in the negative shift of the Fermi level of ZnO. The BiOI/ZnO NRs expanded the absorption region of solar light and constructed an internal electric field in p-n heterojunction, which more efficiently accelerated the migration of electrons, inhibited the carrier’s recombination and improved the photoelectric conversion efficiency of BiOI/ZnO. The Open circuit potential (OCP) of BiOI/ZnO NRs photoanode coupled with the 304 stainless steel negatively shifted to −0.757 mV (vs.SCE), and it could protect stainless steel steadily in 4000 s intermittent illumination, showing the high stability of BiOI/ZnO photoanode. The synergistic effects of p-n heterojunction enable BiOI/ZnO NRs photoanode to exhibit an excellent photocathode protection performance.

High-performance ultraviolet photodetector based on Sn-doped CuO@ZnO nanorod arrays composites

The Sn-doped CuO nanosheets were synthesized on the surface of ZnO nanorods arrays by a two-step method. The as-prepared samples were investigated by X-ray diffraction (XRD), electron microscopy techniques (SEM and EDS), X-ray photoelectron spectroscopy (XPS), UV–Vis spectroscopy, and evaluation of photoelectric performances. With the increase of [Sn4+]/[Cu2+] concentration ratio, the size and number of CuO nanosheets coated on the surface of ZnO nanorods become smaller, and the surface of ZnO nanorods become more and more rough. When the [Sn4+]/[Cu2+] concentration ratio is 2%, the dark current, photocurrent and photoelectric sensitivity of the prepared Sn-doped CuO@ZnO nanorod arrays composites photoelectric devices are 0.038 µA, 141.52 µA and 3724.2, respectively. In this sense, probing the Sn modified CuO@ZnO nanorod arrays composites can elucidate some useful keys for the development of high photoelectric properties.

Nonenzymatic Glucose Sensors of ZnO Nanorods Modified by Au Nanoparticles

In the article, the non-enzymatic glucose sensor Au nanoparticles (NPs) adsorbed on ZnO nanorods (NRs) was synthesized onto glass substrate by the hydrothermal method, and Au NPs were deposited on the surface of ZnO NRs via DC sputter system. The morphologies and crystal structures of ZnO and Au/ZnO NRs were investigated by field-emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The Au NPs adsorbed on the ZnO NR (Au/ZnO) electrode exhibited excellent sensitivity and selectivity for glucose detection. Under an applied bias of 0.2V, the sensitivity of ZnO and Au/ZnO NRs electrodes were 63.4 and 182.96 μA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ∙mM for linear range at 0 to 8 mM. In the interference detective section, the electrodes of ZnO and Au/ZnO NRs exhibited excellent selectivity for glucose detection when the test solutions contain various interfering species, such as ascorbic acid and uric acid. It is demonstrated that the non-enzymatic glucose sensor of the Au/ZnO NR electrode is suitable for glucose detection in human blood samples.

Hierarchical ‘rose-petal’ ZnO/Si surfaces with reversible wettability reaching complete water repellence without chemical modification

Smart surfaces with externally controlled wettability patterns are ubiquitous building blocks for micro-/nanofluidic and lab-on-chip devices, among others. We develop hierarchical surfaces of ZnO nanorods grown on laser-microstructured silicon with reversible photo-induced and heat-induced wettability. The as-prepared surfaces are superhydrophilic, with very low water contact angles (~ 10°), and transition to a wetting state with high water contact angles (~ 150°) when annealed in vacuum. As the annealing temperature increases to 400 °C, the surfaces become completely water-repellent. Even though the annealed surfaces present high water contact angles, at the same time, they are very adhesive for water droplets, which do not roll off even when tilted at 90° or 180o (rose-petal effect), unlike standard hydrophobic surfaces which typically combine high water contact angles with low roll-off angles. The surfaces return to the superhydrophilic state when irradiated with UV light, which indicates a reversible wettability with external stimuli. Based on this transition, we demonstrate local modification of the wetting state of the surfaces by UV irradiation through a mask, which results in directed liquid motion, useful for microfluidic applications. The high contact angles obtained in this work are usually obtained only after chemical modification of the ZnO surface with organic coatings, which was not necessary for the hierarchical surfaces developed here, reducing the cost and processing steps of the fabrication route. These rose-petal surfaces can be used as “mechanical hands” in several applications, such as no-loss transport of small liquid volumes, precision coatings, spectroscopy, and others. Furthermore, the completely water-repellent surfaces, rarely reported elsewhere, may find important applications in frictionless liquid transport for microfluidic and other devices.

Fast and High-Performance Self-Powered Photodetector Based on the ZnO/Metal–Organic Framework Heterojunction

Electrical conductive metal-organic frameworks (EC-MOFs) are emerging as an appealing class of highly tailorable electrically conducting materials with potential applications in optoelectronics. Here, we in situ grew nickel hexahydroxytriphenylene (Ni-CAT) on the surface of ZnO nanorods (NRs). The self-powered photodetectors (PDs) were fabricated with heterojunctions formed at the interface of ZnO NRs and Ni-CAT. With this, the built-in electric field (BEF) can effectively separate the photogenerated electron-hole pairs and enhance the photoresponse. We observe that the PDs based on hybrid ZnO/Ni-CAT with 3 h of growth time (ZnO/Ni-CAT-3) show good photoresponse (137 μA/W) with the fast rise (3 ms) and decay time (50 ms) under 450 nm light illumination without biased voltage. This work provides a facile and controllable method for the growth of the ZnO/Ni-CAT heterojunction with an effective BEF zone, which will benefit their optoelectronic applications.

Fabrication of Vertically Aligned ZnO Nanorods Modified with Dense Silver Nanoparticles as Effective SERS Substrates

Surface-enhanced Raman scattering (SERS) spectroscopy has attracted increasing attention due to its high spectral reproducibility and unique selectivity to target molecules. Here, a facile approach is proposed to prepare Ag nanoparticles modified ZnO nanorod arrays (Ag/ZnO NR arrays). Ag nanoparticles were densely decorated on the surface of ZnO nanorods through silver mirror reaction and subsequent seed-assisted electrodeposition. The prepared Ag/ZnO NR arrays can be used as a sensitive, uniform, and repeatable SERS substrate for the rapid detection of organic dye molecules and biomolecules with concentrations higher than the corresponding limits of detection (LODs). The LODs for rhodamine 6G (R6G), 4-aminothiophenol (PATP) and adenine are calculated to be 1.0 × 10−13 M, 1.6 × 10−12 M and 3 × 10−11 M, respectively. The enhancement factor (EF) of the SERS substrate is estimated to be as high as ~2.7 × 108 when detecting 10−10 M R6G. Particularly, the as-synthesized substrate exhibits high selectivity to multiple components. In addition, the fabricated Ag/ZnO NR arrays can be recycled due to their superior self-cleaning ability and can realize photocatalytic degradation of R6G in water within 1 h driven by UV light, showing that the three-dimensional recyclable SERS substrates have wide applications in environmental pollution monitoring and biomedical analysis.