Routes to Avoiding Chlorine Evolution in Seawater Electrolysis: Recent Perspective and Future Directions Gaurav Bahuguna, Fernando Patolsky ACS Materials Letters, 2024 The prospective of exploring "abundantly available electrolytes", i.e. seawater, as an electrolyte feedstock in electrolyzers is realized recently for supplying unlimited and uninterrupted hydrogen as an energy source. However, seawater splitting possesses severe challenges, due to the presence of different interfering ions. Among these, the presence of chloride ions in seawater poses serious concerns, as it leads to the formation of toxic chlorine-based gaseous and aqueous oxidation products (Cl2, OCl–) during electrolysis. To solve this issue, different approaches are explored, which involve the chemical tuning of the electrolyte, electrodes, and the electrolyzer geometry. However, no report in the literature has summarized these approaches, which can provide a basis for any innovative future research. Herein, for the first time, we have reviewed the current different approaches for avoiding chloride oxidation during seawater electrolysis, critically highlighting their advantages and disadvantages while giving a critical perspective for any future research in the field.
Universal Approach to Direct Spatiotemporal Dynamic In Situ Optical Visualization of On-Catalyst Water Splitting Electrochemical Processes Gaurav Bahuguna, Fernando Patolsky Advanced Science, 2024 Electrochemical reactions are the unrivaled backbone of next‐generation energy storage, energy conversion, and healthcare devices. However, the real‐time visualization of electrochemical reactions remains the bottleneck for fully exploiting their intrinsic potential. Herein, for the first time, a universal approach to direct spatiotemporal‐dynamic in situ optical visualization of pH‐based as well as specific byproduct‐based electrochemical reactions is performed. As a highly relevant and impactful example, in‐operando optical visualization of on‐catalyst water splitting processes is performed in neutral water/seawater. HPTS (8‐hydroxypyrene‐1,3,6‐trisulfonicacid), known for its exceptional optical capability of detecting even the tiniest pH changes allows the unprecedented “spatiotemporal” real‐time visualization at the electrodes. As a result, it is unprecedentedly revealed that at a critical cathode‐to‐anode distance, the bulk‐electrolyte “self‐neutralization” phenomenon can be achieved during the water splitting process, leading to the practical realization of enhanced additive‐free neutral water splitting. Furthermore, it is experimentally unveiled that at increasing electrolyte flow rates, a swift and severe inhibition of the concomitantly forming acidic and basic ‘fronts’, developed at anode and cathode compartments are observed, thus acting as a “buffering” mechanism. To demonstrate the universal applicability of this elegant strategy which is not limited to pH changes, the technique is extended to visualization of hypochlorite/ chlorine at the anode during electrolysis of sea water using N‐(4‐butanoic acid) dansylsulfonamide (BADS). Thus, a unique experimental tool that allows real‐time spatiotemporal visualization and simultaneous mechanistic investigation of complex electrochemical processes is developed that can be universally extended to various fields of research.
SnO2-MWCNT and SnO2-rGO Nanocomposites for Selective Electrochemical Detection in a Mixture of Heavy Metal Ions Mohit Verma, Ankita Kumari, Gaurav Bahuguna, Vikas Singh, Vishakha Pareek, Anandita Dhamija, Shubhendra Shukla, Dibyajyoti Ghosh, Ritu Gupta ACS Applied Nano Materials, 2024 Metal oxide–carbon nanocomposites offer an interesting platform for electrochemical sensing due to the synergistic effect of a highly active semiconducting surface and conducting carbon as the supporting backbone. In this work, the in situ synthesis of SnO 2 with reduced graphene oxide (rGO) led to the formation of small, uniform SnO 2 nanoparticles, measuring 10–20 nm in size, whereas the inclusion of multiwalled carbon nanotubes (MWCNT) resulted in the formation of (200) oriented SnO 2 nanoplatelets of ∼200 nm. X-ray photoelectron spectroscopy (XPS) demonstrates a chemical interaction between Sn and C rather than physical adherence. The cyclic voltammograms (CVs) of SnO 2 –rGO and SnO 2 –MWCNT display high peak current density and small Δ E in comparison to SnO 2, signifying fast electron transfer, reversibility, and enhanced electrochemically active sites. Under optimized experimental conditions of square wave anodic stripping voltammetry (SWASV), the nanocomposites demonstrate high sensitivity (3.9, 9.9, 45.5, and 25.4 mA cm –1 ppb –1 ) and a low detection limit (in ppb) toward Cd 2+, Pb 2+, Cu 2+, and Hg 2+, respectively. The high selectivity of SnO 2 –rGO for Cd 2+ and Pb 2+ ions and SnO 2 –MWCNT for Hg 2+ and Cu 2+ in a complex metal ion environment is encouraging and is probed by using density functional theory (DFT). Additionally, an artificial neural network (ANN)-based model justifies the sensor’s accuracy and precision for real-time, on-site detection of heavy metal ions directly in tap water.
Enabling Unprecedented Ultra-Efficient Practical Direct Seawater Splitting by Finely-Tuned Catalyst Environment via Thermo-Hydrodynamic Modulation Gaurav Bahuguna, Fernando Patolsky Advanced Energy Materials, 2023 Direct sea water splitting as asource of clean renewable energy is indeed a holy grail and necessitates the invention of unprecedented avenues. Toward this goal, for the first time, the effect of thermo‐hydrodynamic processes modulation (electrolyte flow and heating) on water splitting reactions, through the controlling of the nanocatalyst surface environment, is studied thoroughly. A catenated sulphur type‐nickel polysulphide‐based single crystalline, high surface area 3D electrocatalyst (NiS2pSxsurface), with surface‐enriched oxygen evolution reaction (OER, Ni3+) and hydrogen evolution reaction (HER, pSn2−) catalyzing species, is prepared by a single‐step process. Thermo‐hydrodynamic processes‐induced electrochemical analysis demonstrates a dramatic improvement in the electrocatalytic performance of the catalyst, by both flow and temperature modulation. Decoupling contributions from the electrolyte and electrodes heating demonstrate an intrinsic electrode property influence on the overall temperature‐dependent electrochemical performance. Furthermore, a chlorine‐phobic behavior of the NiS2pSxsurface catalyst is observed, even at 80 °C, for direct seawater oxidation, confirming the electrocatalyst potential for direct seawater splitting. Notably, a cell voltage of 1.39 V (at 10 mA cm−2), reaching industrially practical large‐scale of >500 mA cm−2 is observed for additive‐free direct seawater splitting, which is the lowest reported cell voltage to date, even for alkaline additive‐based electrolysers. Consequently, an alternative approach for direct seawater splitting is realized and can be universally extended to any present‐day electrocatalyst platform.
Porous SnO2 nanosheets for room temperature ammonia sensing in extreme humidity Mohit Verma, Gaurav Bahuguna, Sukhwinder Singh, Ankita Kumari, Dibyajyoti Ghosh, Hossam Haick, Ritu Gupta Materials Horizons, 2023 2D SnO2 nanosheets based chemiresistive sensor with microporosity and oxygen rich-surface detects ammonia at room temperature in extreme humidity at ppb levels for breath based early disease diagnostics and healthcare.
Room Temperature Humidity Tolerant Xylene Sensor Using a Sn-SnO2 Nanocomposite Mohit Verma, Gaurav Bahuguna, Arpit Saharan, Snehraj Gaur, Hossam Haick, Ritu Gupta ACS Applied Materials and Interfaces, 2023 Xylene is one of the representative indoor pollutants, even in ppb levels, that affect human health directly. Due to the non-polar and less reactive nature of xylene, its room temperature detection is challenging. This work demonstrates a metallic tin-doped Sn-SnO2 nanocomposite under controlled pH conditions via a simple solvothermal route. The Sn nanoparticles are uniformly distributed inside the SnO2 nanospheres of ∼70 nm with a high specific surface area of 118.8 m2/g. The surface of the Sn-SnO2 nanocomposite exhibits strong affinity toward benzene, toluene, ethylbenzene, and xylene (BTEX) compared to other polar volatile organic compounds (VOCs) such as ethanol, acetone, isopropyl alcohol, formaldehyde, and chloroform tested in this study. The sensor's response is highest for xylene among BTEX molecules. Under ambient room temperature conditions, the sensor exhibits a linear response to xylene in the 1-100 ppm range with a sensitivity of ∼255% at 60 ppm within ∼1.5 s and recovers in ∼40 s. The sensor is hardly affected by humidity variations (40-70%), leading to enhanced reliability and repeatability under dynamic environmental conditions. The meso and microporous nanosphere morphology act as a nanocontainer for non-polar VOCs to diffuse inside the nanostructures, providing easy accessibility. The metallic Sn increases the affinity for less reactive xylene at room temperature. Thus, the nanocatalytic Sn-SnO2 nanocomposite is an active gas/VOC sensing material and provides an effective solution for sensing major indoor pollutants under humid conditions.
Scalable Supercapacitors Snehraj Gaur, Ajay B. Urgunde, Gaurav Bahuguna, S. Kiruthika, Ritu Gupta Springer Series in Materials Science, 2023
Universal light-induced solid-state single-step approach for the in-situ synthesis of porous graphene-embedded nanoparticles G Daffan, G Bahuguna, A Kothuru, F Patolsky Carbon 235, 120077 , 2025 2025 Citations: 11
Universal Approach to Direct Spatiotemporal Dynamic In Situ Optical Visualization of On‐Catalyst Water Splitting Electrochemical Processes (Adv. Sci. 24/2024) G Bahuguna, F Patolsky Advanced Science 11 (24), 2470142 , 2024 2024
Routes to avoiding chlorine evolution in seawater electrolysis: recent perspective and future directions G Bahuguna, F Patolsky ACS Materials Letters 6 (8), 3202-3217 , 2024 2024 Citations: 76
Universal Approach to Direct Spatiotemporal Dynamic In Situ Optical Visualization of On‐Catalyst Water Splitting Electrochemical Processes G Bahuguna, F Patolsky Advanced Science 11 (24), 2401258 , 2024 2024 Citations: 3
SnO 2 –MWCNT and SnO 2 –rGO Nanocomposites for Selective Electrochemical Detection in a Mixture of Heavy Metal Ions M Verma, A Kumari, G Bahuguna, V Singh, V Pareek, A Dhamija, ... ACS Applied Nano Materials 7 (8), 9051-9061 , 2024 2024 Citations: 16
Deciphering the influence of fluorine on the electrochemical performance of MAX and derived MXene by selective electrophilic fluorination G Bahuguna, S Gaur, A Patel, M Verma, S Kiruthika, R Gupta Materials Research Bulletin 169, 112497 , 2024 2024 Citations: 8
Porous SnO 2 nanosheets for room temperature ammonia sensing in extreme humidity M Verma, G Bahuguna, S Singh, A Kumari, D Ghosh, H Haick, R Gupta Materials Horizons 11 (1), 184-195 , 2024 2024 Citations: 28
Why today’s “water” in water splitting is not natural water? Critical up-to-date perspective and future challenges for direct seawater splitting G Bahuguna, F Patolsky Nano Energy 117, 108884 , 2023 2023 Citations: 62
Enabling Unprecedented Ultra‐Efficient Practical Direct Seawater Splitting by Finely‐Tuned Catalyst Environment via Thermo‐Hydrodynamic Modulation (Adv. Energy Mater. 44/2023) G Bahuguna, F Patolsky Advanced Energy Materials 13 (44), 2370181 , 2023 2023 Citations: 1
Enabling Unprecedented Ultra‐Efficient Practical Direct Seawater Splitting by Finely‐Tuned Catalyst Environment via Thermo‐Hydrodynamic Modulation G Bahuguna, F Patolsky Advanced Energy Materials 13 (44), 2301907 , 2023 2023 Citations: 19
Pioneering practical direct sea water splitting via an intrinsically-selective chlorine-phobic nickel polysulphide nanostructured electrocatalyst for pure oxygen evolution G Bahuguna, B Filanovsky, F Patolsky Nano Energy 111, 108439 , 2023 2023 Citations: 54
Scalable supercapacitors S Gaur, AB Urgunde, G Bahuguna, S Kiruthika, R Gupta Handbook of nanocomposite supercapacitor materials IV: next-generation … , 2023 2023 Citations: 2
Room Temperature Humidity Tolerant Xylene Sensor Using a Sn-SnO 2 Nanocomposite M Verma, G Bahuguna, A Saharan, S Gaur, H Haick, R Gupta ACS Applied Materials & Interfaces 15 (4), 5512-5520 , 2023 2023 Citations: 40
SnO 2 Nanoparticle-Reduced Graphene Oxide Hybrids for Highly Selective and Sensitive NO 2 Sensors Fabricated Using a Component Combinatorial Approach M Verma, G Bahuguna, S Shukla, R Gupta ACS Applied Nano Materials 5 (12), 19053-19061 , 2022 2022 Citations: 16
Electronic Structure Engineering of Highly-Scalable Earth-Abundant Multi-Synergized Electrocatalyst for Exceptional Overall Water Splitting in Neutral Medium G Bahuguna, A Cohen, F Boris, B Patolsky Advanced Science , 2022 2022 Citations: 28
Single‐Step Solid‐State Scalable Transformation of Ni‐Based Substrates to High‐Oxidation State Nickel Sulfide Nanoplate Arrays as Exceptional Bifunctional Electrocatalyst for … G Bahuguna, A Cohen, N Harpak, B Filanovsky, F Patolsky Small Methods 6, 2200181 , 2022 2022 Citations: 29
Scalable production of nickel cobaltite nanoplates using solution-processed inks for OER electrocatalysis AB Urgunde, G Bahuguna, A Dhamija, V Kamboj, R Gupta Materials Research Bulletin 142, 111380 , 2021 2021 Citations: 25
Chemical Insights into Electrophilic Fluorination of Tin Oxide Layer for Photoelectrochemical Applications G Bahuguna, M Verma, R Gupta Journal of Materials Chemistry A , 2021 2021 Citations: 31
Fluorinated Nanomaterials for Energy and Sensing Applications G Bahuguna Indian Institute of Technology Jodhpur , 2021 2021
Scalable Fabrication of Scratch-Proof Transparent Al/F-SnO 2 Hybrid Electrodes with Unusual Thermal and Environmental Stability I Mondal, G Bahuguna, MK Ganesha, M Verma, R Gupta, AK Singh, ... ACS applied materials & interfaces , 2020 2020 Citations: 25
MOST CITED SCHOLAR PUBLICATIONS
Routes to avoiding chlorine evolution in seawater electrolysis: recent perspective and future directions G Bahuguna, F Patolsky ACS Materials Letters 6 (8), 3202-3217 , 2024 2024 Citations: 76
Why today’s “water” in water splitting is not natural water? Critical up-to-date perspective and future challenges for direct seawater splitting G Bahuguna, F Patolsky Nano Energy 117, 108884 , 2023 2023 Citations: 62
Thin film coating G Bahuguna, NK Mishra Res. J. Chem 6 (7), 65-72 , 2016 2016 Citations: 61
Pioneering practical direct sea water splitting via an intrinsically-selective chlorine-phobic nickel polysulphide nanostructured electrocatalyst for pure oxygen evolution G Bahuguna, B Filanovsky, F Patolsky Nano Energy 111, 108439 , 2023 2023 Citations: 54
Room Temperature Humidity Tolerant Xylene Sensor Using a Sn-SnO 2 Nanocomposite M Verma, G Bahuguna, A Saharan, S Gaur, H Haick, R Gupta ACS Applied Materials & Interfaces 15 (4), 5512-5520 , 2023 2023 Citations: 40
Innovative Approach to Photo-Chemiresistive Sensing Technology: Surface-Fluorinated SnO 2 for VOC Detection G Bahuguna, I Mondal, M Verma, M Kumar, S Bhattacharya, R Gupta, ... ACS applied materials & interfaces 12 (33), 37320-37329 , 2020 2020 Citations: 34
Green synthesis and characterization of silver nanoparticles using aqueous petal extract of the medicinal plant Combretum indicum G Bahuguna, A Kumar, NK Mishra, C Kumar, A Bahlwal, P Chaudhary, ... Materials Research Express 3 (7), 075003 , 2016 2016 Citations: 32
Chemical Insights into Electrophilic Fluorination of Tin Oxide Layer for Photoelectrochemical Applications G Bahuguna, M Verma, R Gupta Journal of Materials Chemistry A , 2021 2021 Citations: 31
Ultrasensitive Organic Humidity Sensor with High Specificity for Healthcare Applications G Bahuguna, V Adhikary, R Sharma, R Gupta Electroanalysis 32 (1), 1-11 , 2019 2019 Citations: 31
Single‐Step Solid‐State Scalable Transformation of Ni‐Based Substrates to High‐Oxidation State Nickel Sulfide Nanoplate Arrays as Exceptional Bifunctional Electrocatalyst for … G Bahuguna, A Cohen, N Harpak, B Filanovsky, F Patolsky Small Methods 6, 2200181 , 2022 2022 Citations: 29
Surface fluorination of α-Fe2O3 using selectfluor for enhancement in photoelectrochemical properties VC Janu, G Bahuguna, D Laishram, KP Shejale, N Kumar, RK Sharma, ... Solar Energy Materials and Solar Cells 174, 240-247 , 2018 2018 Citations: 29
Porous SnO 2 nanosheets for room temperature ammonia sensing in extreme humidity M Verma, G Bahuguna, S Singh, A Kumari, D Ghosh, H Haick, R Gupta Materials Horizons 11 (1), 184-195 , 2024 2024 Citations: 28
Electronic Structure Engineering of Highly-Scalable Earth-Abundant Multi-Synergized Electrocatalyst for Exceptional Overall Water Splitting in Neutral Medium G Bahuguna, A Cohen, F Boris, B Patolsky Advanced Science , 2022 2022 Citations: 28
Scalable production of nickel cobaltite nanoplates using solution-processed inks for OER electrocatalysis AB Urgunde, G Bahuguna, A Dhamija, V Kamboj, R Gupta Materials Research Bulletin 142, 111380 , 2021 2021 Citations: 25
Scalable Fabrication of Scratch-Proof Transparent Al/F-SnO 2 Hybrid Electrodes with Unusual Thermal and Environmental Stability I Mondal, G Bahuguna, MK Ganesha, M Verma, R Gupta, AK Singh, ... ACS applied materials & interfaces , 2020 2020 Citations: 25
Ni ink-catalyzed conversion of a waste polystyrene–sugar composite to graphitic carbon for electric double-layer supercapacitors AB Urgunde, G Bahuguna, A Dhamija, PP Das, R Gupta ACS Applied Electronic Materials 2 (10), 3178-3186 , 2020 2020 Citations: 21
An organo‐fluorine compound mixed electrolyte for ultrafast electric double layer supercapacitors G Bahuguna, P Ram, RK Sharma, R Gupta ChemElectroChem 5 (19), 2767-2773 , 2018 2018 Citations: 21
Thin film coating through sol-gel technique A Kumar, R Singh, G Bahuguna Res. J. Chem. Sci 6 (1), 65 , 2016 2016 Citations: 21
Enabling Unprecedented Ultra‐Efficient Practical Direct Seawater Splitting by Finely‐Tuned Catalyst Environment via Thermo‐Hydrodynamic Modulation G Bahuguna, F Patolsky Advanced Energy Materials 13 (44), 2301907 , 2023 2023 Citations: 19
Electrophilic Fluorination of Graphitic Carbon for Enhancement in Electric Double Layer Capacitance G Bahuguna, S Chaudhary, R Sharma, R Gupta Energy Technology , 2019 2019 Citations: 18
