Zinc Oxide Semiconductor Research Articles

Influence of UV/Ozone Treatment on Threshold Voltage Modulation in Sol–Gel IGZO Thin‐Film Transistors

AbstractSol–gel indium–gallium–zinc oxide (IGZO) semiconductors are developed as active components of thin‐film transistors (TFTs) because of their high electron mobility, cost‐effective large‐area fabrication, and applicability for flexible substrates. Controlling oxygen vacancies (Vo) in the IGZO semiconductor channel is always problematic for reliable and long‐term operation. Surplus interfacial charges inside the IGZO channel cause negative shifts in threshold voltages (Vth), resulting in depletion‐mode operation and involuntary high current output. The room temperature and rapid (<3 min) modulation of Vth using a novel ultraviolet ozone (UVO) treatment of IGZO layer (In:Ga:Zn = 7:1:2) are reported. Physicochemical and electrical analysis reveals that UVO treatment enables the reduction of Vo and increases MO bonding with invariant contact resistance, resulting in the normalization of Vth close to 0 V and high operational durability under long‐term bias stress. As a proof of concept, this study demonstrates the depletion‐load n‐type inverters comprising depletion and enhancement modes (without & with UVO) on the same substrate that allow high gain (≈10) with a moderate noise margin. This UVO treatment of the active layer is advantageous for the effective modulation of Vth with stable operation under long‐term bias stress and is superior to logic inverters based on single‐mode sol–gel oxide transistors.

N-pentylisatin and ZnO NWs based organic-inorganic hybrid device for broad range photodetection

In this work, a two-terminal and broad spectral range organic-inorganic hybrid photodetector device containing N-pentylisatin -based compound coated semiconducting Zinc oxide (ZnO) nanowires (NWs) on a glass substrate is fabricated. In SEM measurement, the average diameter of the hexagonal top tips, typical for ZnO NWs, was found to be ∼170 nm whereas, the XRD spectrum showed a single well-pronounced peak at 34.36° corresponding to 002 plane of ZnO with an average crystallite size of ∼90 nm, thus confirming the vertical-alignment as well as high crystallinity of ZnO NWs. Moreover, in the SEM images, the N-pentylisatin was observed to fill and cover the sidewalls and top tips of the ZnO NWs. The UV–Vis–NIR optical absorption spectra showed an absorption edge at 2.38eV for N-pentylisatin, 3.08 eV for as-synthesized (pristine) ZnO NWs thin film, and the absorption edge shifted to NIR for hybrid thin-film, i.e., N-pentylisatin coated ZnO NWs thin film. This extended range absorption in the hybrid film is attributed to the optical excitation from the HOMO level of N-pentylisatin to the conduction band (CB) of ZnO NWs. The coated devices showed the photoresponse for all LEDs (IR, red, green, blue), whereas the pristine NWs (without N-pentylisatin coating) showed only response to Blue and White LEDs. The photosensitivity (photo to dark current ratio) of the hybrid device is two to three orders of magnitude larger than the pristine device for the entire Visible (blue, green, red) to IR range. It would be worthwhile to mention that the conductivity of the ZnO NWs thin film was reduced almost 10 to 100 times after coating with N-pentylisatin, thereby indicating that terminating oxygen molecules of the N-pentylisatin act as an electron acceptor.

Integration and characterization of a ferroelectric polymer PVDF-TrFE into the grain boundary structure of ZnO via cold sintering

In this study, the Cold Sintering Process (CSP) is used to design ceramic-polymer composites with Polyvinylidene fluoride Trifluoroethylene (PVDF-TrFE), a ferroelectric co-polymer, as an active intergranular grain boundary phase in a semiconducting Zinc Oxide (ZnO) electroceramic matrix. The conductivity is modeled with Schottky thermionic emission and Fowler-Nordheim tunneling as a function of both temperature and voltage. In addition, through details of the dielectric characterization, the interfaces are also considered with the effective permittivity resulting with a space charge relaxation of the PVDF-TrFE. The Maxwell-Wagner-Sillars (MWS) model was used to predict ~ 3 nm as the thickness of the intergranular PVDF-TrFE phase controlling electrical properties of the composite. Transmission electron microscopy (TEM) investigation of the grain boundary phase confirms the polymer thicknesses to the dimensions predicted from the various electric measurements and subsequent modeling.

Optical and Structural Properties of Controlled pH Variation on Zinc Oxide Nanostructured via Hydrothermal Method

Zinc oxide (ZnO) had been interested today because of their unique and good properties in electronic devices. ZnO nanostructured was synthesized via hydrothermal method by varied the pH value from 7, 8, 9, 10 and 11. The effect of different pH values from 7, 8, 9, 10 and 11 was changed the morphological, structure and optical properties. The samples characterized with Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Ultraviolet- Visible (UV-Vis) spectroscopy. SEM is to observe the morphology images of ZnO nanostructure grains. XRD revealed the detail information on the crystallographic structure and phase formation of the materials. Lastly, UV-vis spectroscopy is to measure the band gap of optical semiconductor. From SEM result, it had shown that the hexagonal nanorods was obtained at pH 7 and pH 11 whereas nanorods is obtain at pH 8, 9 and 10. XRD revealed that the ZnO nanostructure exhibits the hexagonal wurtzite structure and the average crystallite size of ZnO nanoparticle was calculated. UV-Vis spectroscopy shows the absorption of ZnO and band determination from Tauc Plot relation plotter using UV-vis. The resulted show the pH values affect the nanostructure growth of zinc oxide semiconductor properties.

Rational design of ZnO-zeolite imidazole hybrid nanoparticles with reduced charge recombination for enhanced photocatalysis

Semiconducting zinc oxide nanoparticles (ZnO NPs) hold great potential as photocatalysts in wastewater treatment because of their favorable bandgap and cost-effectiveness. Unfortunately, ZnO NPs usually show rapid charge recombination that limits their photocatalytic efficacy significantly. Herein, we report a facile way of modifying ZnO NPs with zeolite imidazole framework-8 (ZIF8). A synergy between the two components may tackle the drawback of fast charge recombination for pristine ZnO NPs. Improved performance of photocatalytic degradation of methylene blue (MB) is confirmed by comparing with pristine ZnO and ZIF8 as the catalysts. The ZIF8 in the composite serves as a trap for photogenerated electrons, thus reducing the rate of charge recombination to enhance the photocatalysis rate. In addition, the hybridization process suppresses the aggregation of ZnO NPs, providing a large surface area and a greater number of active sites. Moreover, a small shift in the absorption band of ZnO@ZIF8 (10) NPs towards higher wavelength, also witnessed a little contribution towards enhanced photocatalytic properties. Mechanistic studies of the photocatalytic process of MB using ZnO@ZIF8 NPs catalyst reveal that hydroxyl radicals are the major reactive oxygen species. The facile hybridization of ZnO with ZIF8 provides a strategy for developing new photocatalysts with wide application potential.

Impact of ZnMnO buffer and SnMnO2 window layer on enhancing the performance of CIGSSe thin-film solar cell

A conventional copper indium gallium sulphur diselenide (CIGSSe) thin-film with double buffer layer solar cell structure of Al/MgF2/ZnO: B/ZnO/ZnMgO/CIGSSe/Mo(S, Se)/Mo is simulated. A high conductivity, low cost and minimum absorption coefficient, manganese doped zinc oxide (Zn1-xMnxO) semiconductor material as a buffer-1 layer is used instead of ZnO in the conventional solar cell. It is observed that the new proposed structure increases the efficiency by 28.80%. Smaller energy band-gap and higher absorption coefficient of ZnO: B window layer material does not absorb the short wavelength photons, thus a decrease in the external quantum efficiency (EQE) of conventional cells is observed. To overcome this, a new structure is proposed to have a wide energy band-gap. A tin-doped manganese oxide (Sn1-xMnxO2) is used as window layer material instead of ZnO: B. A new thin-film solar cell (TFSC) design is proposed where SnMnO2 as window and ZnMnO as buffer-1 is proposed, which helps in instantly absorbing the maximum blue light, reducing recombination losses, increasing efficiency and EQE. This new TFSC design provides a better efficiency of 29.40%.

Optically addressable dielectric elastomer actuator arrays using embedded percolative networks of zinc oxide nanowires.

Dielectric elastomer actuators (DEAs) are electrically driven soft actuators that generate fast and reversible deformations, enabling lightweight actuation of many novel soft robots and haptic devices. However, the high-voltage operation of DEAs combined with the paucity of soft, small high-voltage microelectronics has limited the number of discrete DEAs that can be incorporated into soft robots. This has hindered the versatility as well as complexity of the tasks that they can perform which, in practice, depends on the number of independently addressable actuating elements. This paper presents a new class of optically addressable dielectric elastomer actuators that utilize the photoconductivity of semiconducting zinc oxide nanowires to create optically switchable and stretchable electrical channels. This enables non-contact, optical control of local actuation. To illustrate the versatility of the new capabilities of this integration, we describe the response of dielectric elastomer actuators with integrated photoconductive channels, formed from thin films of percolating semiconducting nanoparticles. By using a switchable array of small light emitting diodes to optically address the actuator array, its actuation can be controlled both spatially and temporally.

Effect of N <sub>2</sub>O treatment on performance of back channel etched metal oxide thin film transistors

In this paper, the rare earth element praseodymium-doped indium tin zinc oxide semiconductor is used as the channel layer of the thin film transistor, and the aluminum oxide-based wet back channel etched thin film transistor is successfully prepared. The effect of N <sub>2</sub>O plasma treatment on the back-channel interface of thin film transistor is studied, and the effect of treatment power and time on device performance are studied in detail. The results show that the good device performance can be obtained under certain power and time treatment, and the prepared device has good thermal stability of positive bias and negative bias under light conditions. The results from high-resolution transmission electron microscopy show that the amorphous structure of the metal oxide semiconductor material can effectively resist the wet etchant, and that no obvious component segregation phenomenon is found. Further, X-ray photoelectric spectroscopy tests show that N <sub>2</sub>O plasma treatment can form an oxygen-rich, low-carrier-concentration interface layer at the interface. On the one hand, it can effectively resist the damage of the back channel caused by the plasma of plasma enhanced chemical vapor deposition (PECVD), and on the other hand, it acts as a passivation body of hydrogen from PECVD plasma, suppressing the generation of low-level donor state of hydrogen. This study provides an important reference for low-cost, high-efficiency thin film transistor performance optimization methods.

ZnO Semiconductor Nanoparticles and Their Application in Photocatalytic Degradation of Various Organic Dyes.

The biosynthesis of oxide semiconductor nanoparticles (NPs) using materials found in nature opens a wide field of study focused on sustainability and environmental protection. Biosynthesized NPs have the capacity to eliminate organic dyes, which pollute water and cause severe damage to the environment. In the present work, the green synthesis of zinc oxide (ZnO) NPs was carried out using Capsicum annuum var. Anaheim extract. The photocatalytic elimination of methylene blue (MB), methyl orange (MO), and Rhodamine B (RhB) in UV radiation was evaluated. The materials were characterized by scanning and transmission electron microscopy (SEM and TEM) and SEM-coupled energy dispersive spectroscopy (EDS), attenuated total reflectance-infrared (ATR-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Photoluminescence (PL), and ultraviolet-visible spectroscopy (UV-Vis). The TEM analysis showed the NPs have an average size of 40 nm and quasi-spherical shape. ATR-IR showed the ZnO NPs contained functional groups from the extract. The analysis through XRD indicated that the NPs have a hexagonal zincite crystal structure with an average crystallite size of approximately 17 nm. The photoluminescence spectrum (PL) presented an emission band at 402 nm. From the UV-Vis spectra and TAUC model, the band-gap value was found to be 2.93 eV. Finally, the photocatalytic assessment proved the ZnO NPs achieved 100% elimination of MB at 60 min exposure, and 85 and 92% degradation of MO and RhB, respectively, at 180 min. This indicates that ZnO NPs, in addition to using a friendly method for their synthesis, manage to have excellent photocatalytic activity in the degradation of various organic pollutants.

ZnO and ZnO/Co3O4 Nanorods for Enhanced Photovoltaic and Photosensors Applications

In this present work, we plan for the first time an all-oxide solar cell and ambient light sensors constructed onto n-type semiconductor zinc oxide along with p-type material having extrinsic type of semiconductor Co3O4 nanowires. The perpendicular ZnO nanorods are dense and are working like scattering layer used for the visible light, even though Co3O4 nano material acting as a visible-light absorber directly. Characterization by SEM, AFM, TEM, XRD, EDS, Optical transmittance, J–V curve. The p-n junction based on metal oxides can operate both such as a photovoltaic (PV) device and a visible light photodetector. The photovoltaic parameters measured beneath simulated sunlight, demonstrating for the first time a PV effect in longitudinal nanowire junctions with decent fill factor (FF, 45%). Furthermore, the heterojunction has also shown an excellent, stable, highly reproducible material, having very fast activity designed for the exposure of visible light. Functional, or effective as possible of the device is essential to strongly improve its functionalities of material. The proposed oxide nanowire p-n junction provides advancement in the field of PV and optoelectronic devices by using inexpensive, stable, and earth-abundant metal oxides.

Epitaxially Integrated Hierarchical ZnO/Au/SrTiO3 and ZnO/Ag/Al2O3 Heterostructures: Three-Dimensional Plasmo-Photonic Nanoarchitecturing.

In this study, we fabricated three-dimensional (3D) hierarchical plasmo-photonic nanoarchitectures by epitaxially integrating semiconducting zinc oxide (ZnO) nanowires with vertically oriented plasmonic gold (Au) and silver (Ag) nanoplatforms and investigated their growth mechanisms in detail. We synthesized 3D hierarchical Au–ZnO nanostructures via a vapor–solid mechanism leading to the epitaxial growth of ZnO nanowires on vertically oriented single-crystalline Au nanowires on a strontium titanate (SrTiO3) substrate. The elongated half-octahedral Au nanowires with a rhombus cross-section were transformed into thermodynamically stable elongated cuboctahedral Au nanowires with a hexagonal cross-section during the reaction. After the transformation, ZnO thin films with six twinned domains were formed on the side planes of the elongated cuboctahedral Au nanowire trunks, and six ZnO nanowire branches were grown on the ZnO thin films. Further, 3D hierarchical Ag–ZnO nanostructures were obtained via the same vapor–solid mechanism leading to the epitaxial growth of ZnO nanowires on vertically oriented Ag nanoplates on an aluminum oxide (Al2O3) substrate. Therefore, the growth mechanism developed herein can be generally employed to fabricate 3D hierarchical plasmo-photonic nanoarchitectures.

ZnO Tips Dotted with Au Nanoparticles-Advanced SERS Determination of Trace Nicotine.

Long-term exposure to nicotine causes a variety of human diseases, such as lung damage/adenocarcinoma, nausea and vomiting, headache, incontinence and heart failure. In this work, as a surface-enhanced Raman scattering (SERS) substrate, zinc oxide (ZnO) tips decorated with gold nanoparticles (AuNPs) are fabricated and designated as ZnO/Au. Taking advantage of the synergistic effect of a ZnO semiconductor with morphology of tips and AuNPs, the ZnO/Au-based SERS assay for nicotine demonstrates high sensitivity and the limit of detection 8.9 × 10−12 mol/L is reached, as well as the corresponding linear dynamic detection range of 10−10–10−6 mol/L. Additionally, the signal reproducibility offered by the SERS substrate could realize the reliable determination of trace nicotine in saliva.

Influence of ZnO nanoadditives on the structural characteristics and dielectric properties of PVA

In this study, different percentages of semiconducting zinc oxide nanoparticles (ZnONPs) are mixed with polyvinyl alcohol (PVA) to create flexible ZnO/PVA polymer nanocomposite films. The characteristics of the prepared films are investigated using differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The XRD pattern shows that the ZnO/PVA composite films were successfully synthesized; while the SEM images show that the ZnONPs are homogeneously dispersed in the PVA polymer chain. Moreover, the DSC indicates an improvement in the thermal stability behavior with increased of ZnONPs concentration. The electrical conductivity, dielectric properties, electric modulus behavior, and the energy density efficiency of the pristine PVA and ZnO/PVA composite films are determined using an LCR meter in the frequency range 102–106 Hz. The dielectric constant of the composite film increased from 0.185 for pristine PVA to 1.389 for 9%ZnO/PVA, and the conductivity is improved from [Formula: see text] S/cm to [Formula: see text] S/cm. This work would open the road for utilizing ZnO/PVA flexible nanocomposite films for wide range of applications such as batteries, super-capacitor and energy storage devices.

Detection of nitrogen atoms as dopants in a zinc oxide crystal lattice incorporated by the effect of a cooling method in a thin film bilayer scheme

The zinc oxide semiconductor can be directed towards p-type or n-type electrical performance depending on the synthesis conditions and fabrication methods, ranging from chemical, sol gel to physical vapor deposition procedures, or the one used in this work: reactive sputtering. Usually this binary oxide, in thin film form, synthesizes into an n-type semiconductor if is fabricated by means of the reactive sputtering method, using an oxygen-poor atmosphere and specific deposition conditions, already established above. However, due to an accident in the synthesis, it was possible to determine the effect that the typical atmosphere at normal atmospheric pressure with 78% nitrogen had on the expected zinc oxide lattice if was abruptly integrated over the scheme. The verification was done using a scratch angle X-ray diffraction characterization, which evidences the incorporation of nitrogen atoms into the zinc oxide crystal by the widening of the lattice parameters. The experimental arrangement analyzed was a bilayer scheme with a first film of n-type zinc oxide and, on this, a second film of the same oxide but p-type. It was possible to conclude that, apart from the desired diode-like behavior of the bilayer, evidenced by the assembly of the half-wave rectifier, there was also evidence of the incorporation of nitrogen in the crystal lattice in the second layer by the notorious shift of the diffraction peak (101).

Photo-patterned oxide films produced using polymeric metal acrylate for low-voltage thin-film transistors

Solution-processed zinc oxide (ZnO) thin-film transistors (TFTs) have received considerable attention as key elements for future electronics due to the ease of fabricating these TFTs and due to the natural abundance and hence low cost of ZnO. However, issues regarding the patterning of solution-processed ZnO semiconductor films unfortunately continue to pose a barrier to their commercialization. In this study, we optimized nanometer-thick photo-curable zinc acrylate (ZnA) films as ZnO precursors and used these precursors to prepare photo-patterned ZnO semiconductors for the fabrication of n-type TFTs. Solution-processed ZnA films were effectively micro-patterned under UV light, because UV-irradiated ZnA film was not solved in etching solvent as a result of photocrosslinking of diacrylate moiety. Through a sol-gel reaction, wurtzite ZnO crystals were stably formed from the photo-patterned ZnA films. After optimizing the film thickness and by using a photo-patterned ZrOx dielectric layer, the prepared ZnO TFT exhibited stable performances with a low-voltage operation within ±2 V. This approach for developing a ZnO semiconductor film can be used to enable the realization of simple, inexpensive, and environmentally friendly solution-processing techniques in electronic device fields.

Monolithic Integration of Vertical Thin-Film Transistors in Nanopores for Charge Sensing of Single Biomolecules.

We propose and fabricate solid-state nanopore devices that monolithically integrate solution-gated, vertical thin-film transistors (TFTs) inside the nanopores for charge-based sensing of translocating biomolecules. The TFTs consist of zinc oxide semiconductor channels and aluminum oxide gate dielectrics, which are both conformally deposited along the inner surfaces of the nanopores via atomic layer deposition. The resultant TFT channel lengths and nanopore diameters both reach the ∼10 nm range. In translocation experiments using λ-DNAs or bovine serum antibody (BSA) proteins, the TFT-nanopore devices demonstrate concurrent detection of the ion conductance blockade signals and modulation signals in the TFT electrical current. The TFT signals show opposite signs for the negatively charged DNAs and positively charged BSAs as well as staircase signal shapes that correspond to the folding and knotting of λ-DNAs. Further experiments under various electrical biases and solution ionic strengths show that the ion blockade signals and the TFT signals have different dependence upon these experimental conditions. The TFT signals are analyzed to be consistent with the field effect sensing of the biomolecular charge, and the induced mirror charge is estimated from the signal amplitudes. This study could be a step forward to achieve charge-based single-biomolecular technology for basic research as well as for biosensing applications. It may also stimulate the development of TFT technologies for conformal integration of semiconductor electronics at the front end of nanostructures.

Impact of Annealing Temperature on Structural, Optical, and Morphological Properties of ZnO Nanoparticles Synthesized by a Simple Precipitation Method

Objective: Herein, we report zinc oxide (ZnO) nanoparticles (NPs) synthesized by a simple precipitation method using zinc acetate dihydrate (Zn(CH3CO2)2. 2H2O) and sodium hydroxide (NaOH) precursors in aqueous media. Method: Synthesized material was annealed at different temperatures to check phase formation and its purity. Results: At room temperature, the sample shows the formation of zinc hydroxide and at high temperature (100, 200, and 300°C) shows the formation of ZnO. Synthesized materials were analyzed by different techniques. X-ray diffraction analysis shows the formation of a hexagonal crystal structure. Morphological features were analyzed by the SEM technique which shows agglomerated nanoparticles. Conclusion: The optical properties of ZnO were studied by using UV analysis and showed intrinsic excitonic transition property of the ZnO semiconductor. Further, with an increase in annealing temperature crystalline size, agglomeration of nanoparticles found to be increased whereas the bandgap decreased.

High-Performance Non-Volatile InGaZnO Based Flash Memory Device Embedded with a Monolayer Au Nanoparticles.

Non-volatile memory (NVM) devices based on three-terminal thin-film transistors (TFTs) have gained extensive interest in memory applications due to their high retained characteristics, good scalability, and high charge storage capacity. Herein, we report a low-temperature (<100 °C) processed top-gate TFT-type NVM device using indium gallium zinc oxide (IGZO) semiconductor with monolayer gold nanoparticles (AuNPs) as a floating gate layer to obtain reliable memory operations. The proposed NVM device exhibits a high memory window (ΔVth) of 13.7 V when it sweeps from −20 V to +20 V back and forth. Additionally, the material characteristics of the monolayer AuNPs (floating gate layer) and IGZO film (semiconductor layer) are confirmed using transmission electronic microscopy (TEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS) techniques. The memory operations in terms of endurance and retention are obtained, revealing highly stable endurance properties of the device up to 100 P/E cycles by applying pulses (±20 V, duration of 100 ms) and reliable retention time up to 104 s. The proposed NVM device, owing to the properties of large memory window, stable endurance, and high retention time, enables an excellent approach in futuristic non-volatile memory technology.

Investigation of shape effect of silver nanostructures and governing physical mechanisms on photo-activity: Zinc oxide/silver plasmonic photocatalyst

Plasmonic composites consisting of silver nanostructures and zinc oxide semiconductor have better photocatalytic performance than pure zinc oxide. To prepare the composites, nanostructures of zinc oxide particles, gold spheres, and three different silver morphology including cubes, spheres, and wires were synthesized. A detailed study of the main mechanisms governing the activity of plasmonic photocatalysts showed that the improvement of photocatalytic performance is attributed to localized surface plasmon resonance-mediated energy transfer from silver to zinc oxide. This mechanism, which is performed using non-radiative (near-field) and radiation (far-field) processes, led to an increase in the concentration of e−/h+ pairs near the semiconductor. We also showed that the increase of the photocatalytic activity depends on the shape of the silver nanostructures in the composites. Our theoretical and experimental studies have shown that composites containing silver cubes have the highest increase of photocatalytic activity compared to other morphologies. The percentage of photocatalytic degradation of methylene blue solution in presence of silver cubes was about 15% higher than that of other morphologies. Therefore, by controlling the shape of noble metal nanostructures, the photocatalytic activity of a semiconductor can be maximized and adjusted.

Microwave-assisted assembly of Ag2O-ZnO composite nanocones for electrochemical detection of 4-Nitrophenol and assessment of their photocatalytic activity towards degradation of 4-Nitrophenol and Methylene blue dye

4-Nitrophenol (4-NP) is an extensively utilized industrial chemical and one of major toxic water pollutant. Therefore, there is an urgent need to monitor the levels of 4-NP from environmental samples as well as its eradication are extremely important. Keeping this as a motivation, this research for the first-time reports microwave-assisted cost-effective synthesis of silver oxide (Ag2O)-zinc oxide (ZnO) composite nanocones (CNCs, 80–100 nm) for simultaneous electrochemical detection and photodegradation of 4-NP from aqueous solutions. The Ag2O-ZnO CNCs modified gold electrode was fabricated for electrochemical detection of 4-NP. Such fabricated sensor exhibited a sensitivity of 1.6 µA µM−1cm−2, wide linear detection range of 0.4–26 µM & 28–326 µM, and a low limit of detection of 23 nM. The sensor also exhibited good selectivity in real water samples. Also, an outstanding photocatalytic performance of Ag2O-ZnO CNCs was evaluated towards UV-assisted degradation of 4-NP and organic water pollutant dye, methylene blue. The Ag2O-ZnO CNCs exhibited excellent electro- and photocatalytic activities due to the formation of p-n nano-heterojunction comprising of p-type Ag2O and n-type ZnO semiconductor nanoparticles within the composite. Therefore, herein reported smart CNCs can be projected as applied nano-system for cost-effective and rapid simultaneous detection and removal of 4-NP from aqueous solutions. Such nano-system can be useful for industrial application where detection and removal of 4-NP is a key issue to resolve.