Reduction Of Nitrate Ions Research Articles

A bioinspired Fe/Mo bimetallic nitride catalyst for efficient electrochemical ammonia synthesis and Zn-nitrate battery

The electrocatalytic nitrate reduction reaction to ammonia (NRA) offers a promising alternative to traditional ammonia synthesis methods. In nature, enzymes containing molybdenum and iron sites catalyze the reduction of nitrate and nitrite ions. Drawing inspiration from these enzymes, we synthesized a carbon-coated nano-octahedra of FeMo-based nitride (FeMoN@C NO) by pyrolyzing phosphomolybdic acid hydrate (POM) doped Fe-NH2-MIL-101 to catalyze NRA. Experimental results demonstrate that in an alkaline environment, FeMoN@C NO exhibits a suitable hydrogen evolution reaction (HER) capacity, and the protons or hydroxyls produced effectively facilitate the hydrogenation reaction in the ammonia synthesis process. Additionally, the introduction of Mo increases the number of active sites and effectively reduces the thermodynamic barrier in NRA, thereby enhancing the rate of ammonia synthesis. As a result, FeMoN@C NO displays outstanding NH3 Faradaic efficiency (FE) of 98.2 % and an NH3 yield of 434.16 µmol/h cm−2. Building upon the excellent electrocatalytic properties of FeMoN@C NO, a new Zn-nitrate battery system is assembled in this work, which exhibits an outstanding peak power density of 3.23 mW cm−2 and an FE of 91.58 % for NH3 production. This work provides a new perspective for designing enzyme-mimicking nitrate reduction catalysts and broadens the application of Zn-based batteries.

Electrochemical sensing of nitrate ions at Cu-immobilized gold electrode in neutral medium

The Cu-immobilized Au surface was electro-catalytically employed for nitrate ions reduction in a neutral solution. According to cyclic voltammetric studies, the Cu/Au electrode has an improved electro-catalytic impact on converting nitrate ions into nitrite ions, governed by a two-electron transfer system. This modified electrode demonstrated good performance in real sample analysis along with good sensitivity (3.2518 $ \mu A \mu M^{-1} cm^{-2}$), long linear detection range (1.2 to 111.4 $\mu M$), a very lower limit of detection (0.85 $\mu M$), an excellent reproducibility. Thus, to determine nitrate ions in an aqueous media, an electrochemical sensor based on a Cu/Au electrode is suggested. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 10(1), 2023 P 75-85

High Ammonia Yield Rate from Dilute Nitrate Solutions Using a Cu(100)-Rich Foil: A Step Closer to Large-Scale Production.

The electrochemical reduction of nitrate (NO3-) ions to ammonia (NH3) provides an alternative method to eliminate harmful NO3- pollutants in water as well as to produce highly valuable NH3 chemicals. The NH3 yield rate however is still limited to the μmol h-1 cm-2 range when dealing with dilute NO3- concentrations found in waste streams. Copper (Cu) has attracted much attention because of its unique ability to effectively convert NO3- to NH3. We have reported a simple and scalable electrochemical method to produce a Cu foil having its surface covered with a porous Cu nanostructure enriched with (100) facets, which efficiently catalyzes NO3- to NH3. The Cu(100)-rich electrocatalyst showed a very high NH3 production rate of 1.1 mmol h-1 cm-2 in NO3- concentration as low as 14 mM NO3-, which is 4-5 times higher than the best-reported values. Increasing the NO3- concentration (140 mM) resulted in an NH3 production yield rate of 3.34 mmol h-1 cm-2. The durability test conducted for this catalyst foil in a flow cell system showed greater than 100 h stability with a Faradaic efficiency greater than 98%, demonstrating its potential to be used on an industrially relevant scale. Further, density functional theory (DFT) calculations have been performed to understand the better catalytic activity of Cu(100) compared to Cu(111) facets toward NO3-RR.

Strategic regulation of nitrogen-containing intermediates for enhanced nitrate reduction over Co3O4/SiC catalyst having multiple active centers

Regulating the intermediates involved in the electrocatalytic nitrate reduction reaction (NO3RR) is crucial for the enhancement of reaction efficiency. However, it remains a great challenge to regulate the reaction intermediates through active site manipulation on the surface of the catalyst. Here, a family of n%-Co3O4/SiC (n = 5, 8, 12, 20) catalysts with a delicate percentage of Co2+ and Co3+ were prepared for NO3RR. We found that Co3+ primarily acts as the active site for NO3− reduction to NO2−, while Co2+ is responsible for the conversion of NO2− to NH3. Moreover, the conversion of these intermediates over the active sites is autonomous and separately controllable. Both processes synergistically accomplish the reduction of nitrate ions to synthesize ammonia. Combining the experimental studies and density functional theory (DFT) calculations, it is discovered the pathway (*NHO→*NHOH→*NH2OH→*NH2→*NH3) is more favorable due to the lower ΔG value (0.25 eV) for the rate-limiting step (*NO→*NHO). The NH3 yield rate of 8%-Co3O4/SiC reached 1.08 mmol/(cm2 h) with a Faradaic efficiency of 96.4% at −0.89 V versus the reversible hydrogen electrode (RHE), surpassing those of most reported non-noble NO3RR catalysts. This strategy not only provides an efficient catalyst for NO3RR but also serves as an illustrative model for the regulation of multi-step reaction intermediates through the design of distinct active sites, thereby presenting a new approach to enhance the efficiency of intricate reactions.

Green Synthesis of Zinc Oxide Nanoparticles Using Clove Oil Extract (Syzygium aromaticum) and Evaluate their Antibacterial Activity against MRSA

There is a crucial need for the development of effective antimicrobial agents due to the rising incidence of hospital-acquired bacterial infections caused by multidrug-resistant microbes, leading to significant mortality and morbidity worldwide. Therefore, the current study aimed to synthesize zinc oxide nanoparticles (SaZnONPs) using clove extract through an environmentally friendly technique and to investigate their antibacterial activity against MRSA (Staphylococcus aureus). Clove extract acts as both a capping and reducing agent in the formation of ZnO-NPs. The formation of SaZnONPs was confirmed using various analytical techniques. Initially, clove extract was incubated with a zinc nitrate solution, and the subsequent change in color of the solution indicated the reduction of zinc nitrate ions to ZnO nanoparticles. UV-visible spectroscopy revealed a surface plasmon resonance band of SaZnONPs at 329.26 nm. Additionally, SEM imaging indicated that the nanoparticles had an average size of 41 nm and exhibited a spherical shape. The antibacterial activity of SaZnONPs was evaluated against MRSA using agar well diffusion and minimum inhibitory concentration assays. The phytochemicals present in clove extract facilitated the synthesis of stable ZnO-NPs, demonstrating promising antibacterial properties.

Environmental remediation approaches by nanoscale zero valent iron (nZVI) based on its reductivity: a review.

The fast rise of organic and metallic pollution has brought significant risks to human health and the ecological environment. Consequently, the remediation of wastewater is in extremely urgent demand and has received increasing attention. Nanoscale zero valent iron (nZVI) possesses a high specific surface area and distinctive reactive interfaces, which offer plentiful active sites for the reduction, oxidation, and adsorption of contaminants. Given these abundant functionalities of nZVI, it has undergone significant and extensive studies on environmental remediation, linking to various mechanisms, such as reduction, oxidation, surface complexation, and coprecipitation, which have shown great promise for application in wastewater treatment. Among these functionalities of nZVI, reductivity is particularly important and widely adopted in dehalogenation, and reduction of nitrate, nitro compounds, and metal ions. The following review comprises a short survey of the most recent reports on the applications of nZVI based on its reductivity. It contains five sections, an introduction to the theme, chemical reduction applications, electrolysis-assisted reduction applications, bacterium-assisted reduction applications, and conclusions about the reported research with perspectives for future developments. Review and elaboration of the recent reductivity-dependent applications of nZVI may not only facilitate the development of more effective and sustainable nZVI materials and the protocols for comprehensive utilization of nZVI, but may also promote the exploration of innovative remediation approaches based on its reductivity.

(Invited) Tuning the Activity of Iron Phosphide Electrocatalysts for Sustainable Energy Conversion

Electrocatalysis is a promising approach for the sustainable conversion of renewable energy sources, such as solar and wind power, into chemical energy that can be stored and used on demand. By harnessing renewable electricity to drive electrochemical reactions, we can produce fuels and chemicals in a way that is both clean and cost-effective. As we continue to develop new electrocatalytic materials and improve the efficiency of existing processes, the potential for electrocatalysis to transform our energy system will only continue to grow.We report the use of iron phosphide (Fe2P, FeP) in several electrocatalytic applications, such as reduction of nitrate ions (NO3), hydrogen and oxygen evolution studies. The electrochemical reduction of the nitrate ion (NO3), a widespread water pollutant, to valuable ammonia (NH3) is a promising approach to achieving green energy conservation. Particularly, FeP and Fe2P phases were successfully demonstrated as efficient catalysts for NH3 generation. Detection of the in-situ formed product using a bi-potentiostat was achieved by electrooxidation of NH3 to nitrogen (N2) on a Pt electrode. The Fe2P catalyst exhibits the highest Faradaic efficiency (96%) for NH3 generation with a yield (0.25 mmol h−1 cm-−2 or 2.10 mg h−1 cm−2) at −0.55 V vs. reversible hydrogen electrode (RHE). To get relevant information about the reaction mechanisms and the fundamental origins behind the better performance of Fe2P, density functional theory (DFT) calculations were performed.In addition to NH3 synthesis, the iron phosphide catalyst was used in electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) studies. To enhance the catalytic activities of the obtained iron phosphide particles, heat-treatments were carried out at elevated temperatures. Heat-treatment at 500°C under a reductive atmosphere induced structural changes in the samples: (i) Fe2P yielded a pure Fe3P phase (Fe3P−500°C) and (ii) FeP transformed into a mixture of iron phosphide phases (Fe2P/FeP−500°C). The electrocatalytic activities of heat-treated Fe3P−500°C, and Fe2P/FeP−500°C catalysts were studied for hydrogen evolution reaction (HER) in 0.5 M H2SO4. The lowest HER electrode potential of 110 mV vs. a reversible hydrogen electrode (RHE) at 10 mA cm−2 was achieved with a Fe2P/FeP−500°C catalyst. The intrinsic activity of FeP catalysts was also tuned and studied for OER.

Copper-Based Catalyst Yields Unusual Ammonia Yield in Nitrate Electroreduction

The electrochemical reduction of nitrate (NO3 -) ions into ammonia (NH3) provides an alternative method to produce highly valuable NH3 as well as eliminating harmful NO3 - pollutants. A variety of catalysts have been explored in recent times, however the NH3 production rate is far behind that of industrial Haber Bosch process which poses a major challenge for large scale synthesis. Herein, we have adopted an electrochemical synthetic route to produce highly porous copper nanoparticle enriched with (100) facets over copper foil containing which efficiently catalyzes NO3 - to NH3. Cu(100) rich electrocatalyst shows a significantly high NH3 production rate of greater than 1.0 mmol h-1 cm-2 even in the dilute NO3 - concentration of 14 mM, which is 4 to 5 times higher than the best reported values. Increasing the NO3 -concentration to 140 mM resulted in an NH3 production rate greater than 3.0 mmol h-1 cm-2, demonstrating that the catalyst is active in a wide range of NO3 - concentrations. Furthermore, durability test conducted in a flow system shows more than 100 h stability while maintaining a faradaic efficiency of greater than 98 %. Thus, we have successfully demonstrated the suitability of our catalyst at an industrially relevant scale.

Understanding the Synergy between Fe and Mo Sites in the Nitrate Reduction Reaction on a Bio‐Inspired Bimetallic MXene Electrocatalyst

AbstractMo‐ and Fe‐containing enzymes catalyze the reduction of nitrate and nitrite ions in nature. Inspired by this activity, we study here the nitrate reduction reaction (NO3RR) catalyzed by an Fe‐substituted two‐dimensional molybdenum carbide of the MXene family, viz., Mo2CTx : Fe (Tx are oxo, hydroxy and fluoro surface termination groups). Mo2CTx : Fe contains isolated Fe sites in Mo positions of the host MXene (Mo2CTx) and features a Faradaic efficiency (FE) and an NH3 yield rate of 41 % and 3.2 μmol h−1 mg−1, respectively, for the reduction of NO3− to NH4+ in acidic media and 70 % and 12.9 μmol h−1 mg−1 in neutral media. Regardless of the media, Mo2CTx : Fe outperforms monometallic Mo2CTx owing to a more facile reductive defunctionalization of Tx groups, as evidenced by in situ X‐ray absorption spectroscopy (Mo K‐edge). After surface reduction, a Tx vacancy site binds a nitrate ion that subsequently fills the vacancy site with O* via oxygen transfer. Density function theory calculations provide further evidence that Fe sites promote the formation of surface O vacancies, which are identified as active sites and that function in NO3RR in close analogy to the prevailing mechanism of the natural Mo‐based nitrate reductase enzymes.

Understanding the Synergy between Fe and Mo Sites in the Nitrate Reduction Reaction on a Bio-Inspired Bimetallic MXene Electrocatalyst.

Mo- and Fe-containing enzymes catalyze the reduction of nitrate and nitrite ions in nature. Inspired by this activity, we study here the nitrate reduction reaction (NO3 RR) catalyzed by an Fe-substituted two-dimensional molybdenum carbide of the MXene family, viz., Mo2 CTx : Fe (Tx are oxo, hydroxy and fluoro surface termination groups). Mo2 CTx : Fe contains isolated Fe sites in Mo positions of the host MXene (Mo2 CTx ) and features a Faradaic efficiency (FE) and an NH3 yield rate of 41 % and 3.2 μmol h-1 mg-1 , respectively, for the reduction of NO3 - to NH4 + in acidic media and 70 % and 12.9 μmol h-1 mg-1 in neutral media. Regardless of the media, Mo2 CTx : Fe outperforms monometallic Mo2 CTx owing to a more facile reductive defunctionalization of Tx groups, as evidenced by in situ X-ray absorption spectroscopy (Mo K-edge). After surface reduction, a Tx vacancy site binds a nitrate ion that subsequently fills the vacancy site with O* via oxygen transfer. Density function theory calculations provide further evidence that Fe sites promote the formation of surface O vacancies, which are identified as active sites and that function in NO3 RR in close analogy to the prevailing mechanism of the natural Mo-based nitrate reductase enzymes.

Photoelectrochemical nitrate reduction to ammonia over BiVO4/2D macromolecular with extremely low energy consumption

Photoelectrochemical nitrate ions (NO3−) reduction reaction (PEC NITRR) to produce ammonia (NH3) at ambient conditions could not only solve the problem of NO3− pollution, but also transform the NO3− to hydrogen carrier (NH3). Herein, we introduced Cu2+ by construction of BiVO4/CuPc, effectively adsorbed target reactant NO3− and further promote its effective conversion to NH3. This unique catalyst structure leads to a desirable NH3 yield (rNH3 = 12.98 μg h−1 cm−2) and Faraday efficiency (FE = 20.36%) at 0.1 V vs. RHE. Therefore, this work provides a new perspective for establishing a low energy consumption PEC NITRR to achieve sustainable transformation of pollutants.

Efficient nitrate reduction in water using an integrated photocatalyst adsorbent based on chitosan-titanium dioxide nanocomposite.

Globally, there exists a huge concern on the increased discharge of nitrates to the natural water resources out of various anthropogenic activities as it causes serious environmental pollution and associated harmful effects. In the present work, sol-gel-derived functional nanocomposites based on silver (Ag) and nitrogen (N)-doped titanium dioxide (TiO2)-coated chitosan nanocomposites were successfully synthesized in the form of beads, and their application for the reduction of nitrates in water was studied. The synthesized nanocomposite beads were characterized for their structural, textural, and morphological features using X-ray diffraction analysis, Fourier transform infrared spectroscopy, UV-visible spectroscopy, BET surface area analysis, Scanning electron microscopy, Transmission electron microscopy, and X-ray photoelectron spectroscopy. A uniform coating of doped titania species on the chitosan porous structure was achieved through electrostatic interaction. Adsorption/photocatalytic reduction of nitrates was further carried out using functional nanocomposite beads by monitoring the nitrate concentration of the model contaminated water, in an adsorption study under dark condition and photocatalytic study under UV/sunlight for a definite time period. Drying conditions of the nanocomposite beads were found to have a significant effect on the adsorption cum photocatalytic efficiencies of the nanocomposite. The freeze-dried chitosan-titania nanocomposite beads containing 0.5mol% Ag exhibited an adsorption efficiency of ~ 43.5% (under dark for 30min) and photocatalytic reduction capability of ~ 95% (under sunlight for 2h), whereas the oven dried beads of the same composition exhibits adsorption and photocatalytic efficiencies of 40% (under dark for 30min) and 70% (under UV light for 2h) respectively, towards the reduction of nitrate ions in an aqueous solution. Continuous flow adsorption cum photocatalytic study using the oven-dried nanocomposite beads was also carried out with the help of an experimental setup fabricated in-house and under varying experimental conditions such as flow rate, bed height, and concentration of feed solution. Nitrate reduction efficiency of 87.6% and an adsorption capacity of 7.9mgg-1 were obtained for the nanocomposite beads in the continuous flow adsorption cum photocatalysis experiment for up to 8h when using an inlet concentration of 100ppm, bed height 12cm, and flow rate 5.0mLmin-1. A representative fixed-bed column adsorption experiment performed with oven dried nanocomposite beads in a real groundwater sample collected from the Palakkad District of Kerala shows promising results for nitrate reduction (85.9% efficiency) along with a significant removal rate for the other anions as well. Thus, the adsorption cum photocatalytic nitrate reduction efficiency of the functional nanocomposite material makes them suitable for the reduction of nitrates from water/wastewater through an integrated nanocomposite approach.

Nitrates Removal from Simulated Groundwater Using Nano Zerovalent Iron Supported by Polystyrenic Gel.

The main objectives of this present paper were to indicate the immobilization of nano zerovalent iron (nZVI) onto a polymeric material (Purolite A400) and the synthesis of the polymeric material (A400-nZVI) through sodium borohydride (NaBH4) reduction. The obtained polymeric material (A400-nZVI) was used for the nitrate ions removal from a simulated groundwater at different conditions. The polymeric materials, without and with nano zerovalent iron (A400 and A400-nZVI), were characterized trough the FTIR, SEM-EDAX, XRD, and TGA analysis. The analysis confirmed the presence of nano zerovalent iron (nZVI) onto the polymeric material (A400). The adsorption capacity of A400-nZVI, used as polymeric adsorbent, was evaluated by kinetic and thermodynamic studies. The obtained experimental results indicated that the nitrate ions reduction was fitted well by models: pseudo-second-order kinetic and Freundlich isotherm. According to the kinetic model results, a reaction mechanism could exist in the stage of reactions. The higher value of removal nitrate (>80%) was obtained under acidic condition. The results indicated that the obtained polymeric material (A400-nZVI) can be considered as a potential polymeric adsorbent for different pollutants from groundwater and wastewater.

Electrocatalytic reduction of nitrate ions in neutral medium at coinage metal-modified platinum electrodes.

Nitrate is a water-soluble toxic pollutant that needs to be excluded from the environment. For this purpose, several electrochemical studies have been conducted but most of them focused on the nitrate reduction reaction (NRR) in alkaline and acidic media while insignificant research is available in neutral media with Pt electrode. In this work, we explored the effect of three coinage metals (Cu, Ag, and Au) on Pt electrode for the electrochemical reduction of nitrate in neutral solution. Among the three electrodes, Pt-Cu exhibited the best catalytic activity toward NRR, whereas Pt-Au electrode did not show any reactivity. An activity order of Pt-Cu > Pt-Ag > Pt-Au was observed pertaining to NRR. The Pt-Ag electrode produces nitrite ions by reducing nitrate ions ([Formula: see text]. Meanwhile, at Pt-Cu electrode, nitrate reduction yields ammonia via both direct ([Formula: see text] and indirect ([Formula: see text] reaction pathways depending on the potential. The cathodic transfer coefficients were estimated to be ca. 0.40 and ca. 0.52, while the standard rate constants for nitrate reduction were calculated as ca. 2.544 × 10-2cm.s-1 and ca. 1.453 × 10-2cm.s-1 for Pt-Cu and Pt-Ag electrodes, respectively. Importantly, Pt-Cu and Pt-Ag electrodes execute NRR in the neutral medium between their respective Hydrogen-Evolution Reaction (HER) and Open-Circuit Potential (OCP), implying that on these electrodes, HER and NRR do not compete and the latter is a corrosion-free process.

Cu-electrodeposited gold electrode for the sensitive electrokinetic investigations of nitrate reduction and detection of the nitrate ion in acidic medium

The electro-catalytic reduction of nitrate ion in acidic media was observed at the Cu-electrodeposited Au surface. The voltammetric analysis represented that the Cu/Au electrode has an enhanced catalytic activity towards nitrate reduction in acidic medium through by eight electrons transfer process. Ammonia (NH3) was produced from the reduction of nitrate (NO3–) which followed a concerted reaction pathway as the value of transfer coefficient was 0.45 at Cu/Au electrode in the acidic medium. The value of standard rate constant and open circuit potential was evaluated as 2.48 × 10−4 cms−1 and 0.10 V respectively. This Cu/Au electrode displayed a good sensitivity (5.9378 μAµM−1cm−2) and lower detection limit (LOD: 0.52 µM) towards the reduction of nitrate ion and exhibited excellent performance in real sample analysis.

Water Purification By Removing Chemical Materials From Water By Electrochemical Methods

The current Study gives an Electrocoagulation Process for the Reduction of Nitrate Ions from Aqueous Solutions, to Meet the Standards of Water for Drinking Purposes.The effect variables such as pH Init, Current Density (i), Temperature (T), and Time (t) on the Reduction Efficiency was studied in Batch Reactor Using Aluminium Electrodes. The Optimal Reduction Conditions Were Proposed to be at pH = 7, Temperature of 30◦ C, Current Density 2.604 mA.cm-2 and Time of 120 min. The Results Showed that the Reduction Percentages for NO3- were 88.18% by Using Al Electrodes at 120 min. The Electrode Consumption was (0.167) kg/m3 and the Mean Energy Consumed was WSP= (3.5) kWh/m3.

Comparative study of electrodeposited copper nanoparticles on different substrates for their use in the reduction of nitrate ions

A comparative analysis of the electrodeposition of copper nanoparticles (CuNPs) was studied on highly oriented pyrolytic graphite (HOPG) and vitreous carbon (VC) substrates from solutions containing different supporting electrolytes (Na2SO4 and H2SO4).Voltammetric results indicated the presence of a single cathodic process, corresponding to the reduction reaction of Cu2+ ions to Cuo, for the solutions studied, using the HOPG substrate. The solution containing Na2SO4 as supporting electrolyte was found to be more effective because the copper reduction process occurs at more positive potential values, reaching the highest current density. For the VC substrate, two cathodic processes were evidenced, with the formation of Cu+ ions as intermediate species. As in the HOPG substrate, the use of the solution containing Na2SO4 showed the better behavior for copper electrodeposition, being the most favored process on VC. This behavior could be explained by considering the existence of structural defects in the VC, which would facilitate Cu nucleation.The nucleation and growth kinetics of CuNPs on HOPG electrodes corresponded predominantly to a model including progressive nucleation on active sites, and diffusion controlled growth, presenting a good correlation with the scanning electron microscopy images. For VC substrates, the kinetics analysis did not yield conclusive results. Different morphological features of Cu deposits were observed on HOPG and VC, presenting the former a larger covered area.The HOPG/CuNPs modified electrodes evidenced an enhancement in the catalytic activity towards the nitrate reduction reaction.

Photocatalytic removal of nitrate from water using activated carbon-loaded with bimetallic Pd-Ag nanoparticles under natural solar radiation

The increase of nitrate contamination of surface and groundwater has raised a concern, because of its impact on both environment and human health. In this study, photocatalysis for nitrate treatment in water was conducted using activated carbon prepared from date palm stone decorated with single and bimetals nanoparticles using solar radiation. The prepared catalyst was characterized by XPS, SEM, EDX, TGA, and surface area analyzer instruments. The photocatalytic effect of the prepared catalyst was studied using nitrate solution and acid scavengers with different concentrations. Significant photocatalytic activity was observed for activated carbon when modified with Pd–Ag. The obtained results showed that the conversion of nitrate takes place mainly through nitrogen gas (N2) rather than nitrite (NO2–) or ammonium (NH4+). Formic acid as a hole scavenger with 0.05 M shows the maximum conversion for nitrate. The prepared photocatalyst shows stability for five cycles of nitrate ion reduction. Moreover, the results showed that the prepared catalyst could be applied for the removal of nitrate from groundwater and river water samples.

Synthesis of Fe–TiO2/Al2O3 nanocatalyst for photocatalytic reduction of nitrate ion from aqueous solution under visible light and UV irradiation

Synthesis of Fe–TiO2/Al2O3 nanocatalyst for photocatalytic reduction of nitrate ion from aqueous solution under visible light and UV irradiation

Microdevice for the Reduction of Nitrate Ions Using Copper Micro-Tubular Carriers

Microdevice for the Reduction of Nitrate Ions Using Copper Micro-Tubular Carriers