02138nas a2200253 4500008004100000022001400041245016900055210006900224260000800293300001400301490000600315520119100321653001901512653003001531653002001561653003201581653002801613100002801641700002501669700001801694700002101712700002401733856012701757 2017 eng d a2196-021600aNitrogen-doped graphene with a three-dimensional architecture assisted by carbon nitride tetrapods as an efficient metal-free electrocatalyst for hydrogen evolution0 aNitrogendoped graphene with a threedimensional architecture assi cOCT a2643-26520 v43 aCurrent polymer membrane-based electrolyzers use Pt as a cathode catalyst for efficient reduction of water. The high cost of Pt-based catalysts forces researchers to develop alternative electrocatalysts. Here, a simple strategy has been proposed to synthesize a metal-free electrocatalyst for the hydrogen evolution reaction (HER) by high-temperature annealing of graphene oxide-coated melamine foam. The prepared catalyst possesses both structural and functional advantages with its three-dimensional (3D) interconnected arms of carbon nitride (CNx) backbone wrapped with nitrogen-doped graphene (N-RGO) sheets (CNx@N-RGO). CNx@N-RGO faces only a 193 mV overpotential to achieve a current density of 10mAcm(-2), which is far superior to the previously reported Pt-free systems. Along with the high exchange current density 34.7 x 10(-6)A cm(-2) and low Tafel slope of 54 mV dec(-1), CNx@N-RGO follows a Volmer-Heyrovsky mechanism for the HER. DFT calculations show that the synergy between CNx and N-RGO facilitates good electrical coupling between the two moieties and provides optimal binding to H+ ions on the catalyst that, in turn, results in efficient reduction of hydrogen ions.10acarbon nitride10aDensity functional theory10aelectrocatalyst10ahydrogen evolution reaction10anitrogen doped graphene1 aGangadharan, Pranav, K.1 aUnni, SreeKuttan, M.1 aKumar, Nandha1 aGhosh, Prasenjit1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/nitrogen-doped-graphene-three-dimensional-architecture-assisted-carbon-nitride-tetrapods02877nas a2200253 4500008004100000022001400041245014000055210006900195260000900264300001600273490000700289520193800296653003202234653002902266653002402295653002702319653002802346653002802374100002002402700002402422700002302446700002402469856013002493 2019 eng d a1944-824400a[MoS4](2-)-Intercalated NiCo-layered double hydroxide nanospikes: an efficiently synergized material for urine to direct H-2 generation0 aMoS42Intercalated NiColayered double hydroxide nanospikes an eff cJUL  a25917-259270 v113 a

Substituting the energy-uphill water oxidation half-cell with readily oxidizable urea-rich urine, a ground-breaking bridge is constructed, combining the energy-efficient hydrogen generation and environmental 6 protection. Hence, designing a robust multifunctional electrocatalyst is desirable for widespread implementation of this waste to fuel technology. In this context, here, we report a simple tuning of the electrocatalytically favorable characteristics of NiCo-layered double hydroxide by introducing [MoS4]2- in its interlayer space. The [MoS4]' insertion as well as its effect on the electronic structure tuning is thoroughly studied via X-ray photoelectron spectroscopy in combination with electrochemical analysis. This insertion induces overall electronic structure tuning of the hydroxide layer in such a way that the designed catalyst exhibited favorable kinetics toward all the required reactions of hydrogen generation. This is why our homemade catalyst, when utilized both as a cathode and anode to fabricate a urea electrolyzer, required a mere X1.37 V cell potential to generate sufficient H2 by reaching the benchmark 10 mA cm-2 in 1 M KOH/0.33 M urea along with long-lasting catalytic efficiency. Other indispensable reason of selecting [MoS4]2- is its high-valent nature making the catalyst highly selective and insensitive to common catalyst-poisoning toxins of urine. This is experimentally supported by performing the real urine electrolysis, where the nanospike-covered Ni foam-based catalyst showed a performance similar to that of synthetic urea, offering its industrial value. Other intuition of selecting [MoS4]2- was to provide a ligand-based mechanism for hydrogen evolution half-cell [hydrogen evolution reaction (HER)] to preclude the HER-competing oxygen reduction. Another crucial point of our work is its potential to avoid the mixing of two explosive product gases, that is, H2 and O-2.

10ahydrogen evolution reaction10aLayered double hydroxide10anickel oxyhydroxide10asewage denitrification10aurea oxidation reaction10aurine/urea electrolysis1 aNadeema, Ayasha1 aKashyap, Varchaswal1 aGururaj, Rakshitha1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/mos42-intercalated-nico-layered-double-hydroxide-nanospikes-efficiently-synergized-material02193nas a2200241 4500008004100000022001400041245016800055210006900223260000800292300001400300490000600314520127100320653002201591653002401613653002601637653003201663653003001695100002001725700003001745700002701775700002401802856012501826 2020 eng d a2196-021600aCo@CoAl-layered double hydroxide/nitrogen-doped graphene composite catalyst for Al-H2O-based batteries: simultaneous hydrogen production and electricity generation0 aCoCoAllayered double hydroxidenitrogendoped graphene composite c cJUN a2582-25910 v73 a

Currently, the low energy efficiency of water electrolysis has compelled research toward the development of novel and energy-effective strategies for low-cost H-2 generation. In this context, we report a new concept of simultaneous H-2 and electricity generation by separating out the exothermic self-sustained Al-H2O reaction via electrochemistry. In addition, to catalyze the cathodic water reduction reaction, a single-pot and environmentally benign synthesis method is adopted. It results in the design of an electrocatalyst composed of Co@CoAl-layered double hydroxide core-shell nanospheres anchored over in situ generated N-doped graphene. Toward the water reduction reaction, the designed catalyst shows a negative voltage shift of mere around 113 mV with respect to the commercial Pt/C catalyst to reach the benchmark 10 mA cm(-2), with excellent stability of approximately 86 % voltage retention after 12 h of continuous operation. The catalytic superiority of our material is evident when taken for battery-level testing; the fabricated device was able to deliver an average output voltage of around 0.95 V at a discharge current density of 5 mA cm(-2) along with H-2 liberation, which was also detected and quantified through gas chromatography.

10aAl-H2O fuel cells10achronopotentiometry10acore-shell structures10ahydrogen evolution reaction10alayered double hydroxides1 aNadeema, Ayasha1 aKharabe, Geeta, Pandurang1 aBiswal, Dibya, Prakash1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/cocoal-layered-double-hydroxidenitrogen-doped-graphene-composite-catalyst-al-h2o-based01629nas a2200265 4500008004100000022001400041245013100055210006900186260000800255300001400263490000600277520070900283653002500992653003201017653003001049653001501079653002001094100001901114700001901133700001801152700001801170700002001188700002501208856013001233 2020 eng d a2574-096200aStress-induced electronic structure modulation of manganese-incorporated Ni2P leading to enhanced activity for water splitting0 aStressinduced electronic structure modulation of manganeseincorp cFEB a1271-12780 v33 a

The cornerstone of the emerging hydrogen economy is hydrogen production by water electrolysis with concomitant oxygen generation. Incorporating a third element in metal phosphides can tune the crystalline and electronic structure, hence improving the electrocatalytic properties. In this work, Mn-doped Ni2P with varying ratios of Mn and Ni has been explored as excellent catalysts for water splitting. A complete cell made of the best catalyst Ni1.5Mn0.5P electrodes showed low voltage of 1.75 V at a current density of 10 mA cm(-2) due to enhanced electrical conductivity, induction of tensile stress, enhanced electrochemical surface area, and increased electric dipole upon Mn incorporation.

10aElectronic Structure10ahydrogen evolution reaction10aOxygen Evolution Reaction10aphosphides10awater splitting1 aSarkar, Shreya1 aDheer, Lakshay1 aVinod, C., P.1 aThapa, Ranjit1 aWaghmare, Umesh1 aPeter, Sebastian, C. uhttp://library.ncl.res.in/content/stress-induced-electronic-structure-modulation-manganese-incorporated-ni2p-leading-enhanced02730nas a2200277 4500008004100000022001400041245015700055210006900212260000900281300001400290490000600304520175500310653001902065653003002084653003202114653001802146653001802164100001702182700001902199700001702218700002302235700002202258700003002280700001802310856012402328 2021 eng d a2574-096200aOne-dimensional multichannel g-C3N4.7 nanostructure realizing an efficient photocatalytic hydrogen evolution reaction and its theoretical investigations0 aOnedimensional multichannel gC3N47 nanostructure realizing an ef cAPR  a3118-31290 v43 a

The emerging metal-free carbon nitride (C3N4) offers prominent possibilities for realizing the highly effective hydrogen evolution reaction (HER). However, its poor surface conductivity and insufficient catalytic sites hinder the HER performance. Herein, a one-dimensional vermicular rope-like graphitic carbon nitride nanostructure is demonstrated that consists of multichannel tubular pores and high nitrogen content, which is fabricated through a cost-effective approach having the final stoichiometry g-C3N4.7 for HER application. The present g-C3N4.7 is unique owing to the presence of abundant channels for the diffusion process, modulated surface chemistry with rich- electroactive sites from N-electron lone pairs, greatly reduced recombination rate of photoexcited exciton pairs, and a high donor concentration (4.26 x 10(17) cm(3)). The catalyst offers a visible-light-driven photocatalytic H-2 evolution rate as high as 4910 mu mol h(-1)g(-1) with an apparent quantum yield of 14.07% at band gap absorption (2.59 eV, 479 nm) under 7.68 mW cm(-2) illumination. The number of hydrogen gas molecules produced is 1.307 x 10(15) s(-1) cm(-2), which remained constant for a minimum of 18 h of repeated cycling in the HER without any degradation of the catalyst. In density functional theory calculations, a significant change in the band offset is observed due to N doping into the system in favor of electron catalysis. The theoretical band gap of a monolayer of g-C3N4.7 was enormously reduced because of the presence of additional densities of states from the doped N atom inside the band gap. These impurity or donor bands are formed inside the band gap region, which ultimately enhance the hydrogen ion reduction reaction enormously.

10acarbon nitride10aDensity functional theory10ahydrogen evolution reaction10anitrogen-rich10aPhotocatalyst1 aAntil, Bindu1 aKumar, Lakshya1 aRanjan, Ravi1 aShenoy, Sulakshana1 aTarafder, Kartick1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka uhttp://library.ncl.res.in/content/one-dimensional-multichannel-g-c3n47-nanostructure-realizing-efficient-photocatalytic01817nas a2200277 4500008004100000022001400041245012800055210006900183260000900252300001400261490000700275520088200282653002001164653002101184653003201205653001801237653002601255100001901281700002001300700001601320700002101336700002301357700001801380700002501398856011601423 2021 eng d a1864-563100aStructure-tailored non-noble metal-based ternary chalcogenide nanocrystals for pt-like electrocatalytic hydrogen production0 aStructuretailored nonnoble metalbased ternary chalcogenide nanoc cAUG  a3074-30830 v143 aA facile microwave-assisted strategy was employed to synthesize Ni3Bi2S2 nanocrystals. Variation in the synthesis conditions tuned the composition of monoclinic and orthorhombic phases of Ni3Bi2S2. The electrochemical hydrogen evolution activity of the catalyst with highest percentage of monoclinic phase demonstrated a negligible onset potential of only 24 mV close to that of state-of-the-art Pt/C with an overpotential as low as 88 mV. Density functional theory calculations predicted the monoclinic phase exhibit the lowest adsorption free energy corresponding to hydrogen adsorption (Delta GadsH*) and, therefore, the highest hydrogen evolution activity amongst the considered phases. The quasi-2D structure of monoclinic phase facilitated an increased charge-transfer between Ni and Bi, favoring the downward shift of the d-band center to enhance the catalytic activity.10acharge transfer10aelectrocatalysis10ahydrogen evolution reaction10aNanomaterials10aternary chalcogenides1 aSarkar, Shreya1 aRawat, Abhishek1 aDas, Tisita1 aGaboardi, Mattia1 aChakraborty, Sudip1 aVinod, C., P.1 aPeter, Sebastian, C. uhttp://library.ncl.res.in/content/structure-tailored-non-noble-metal-based-ternary-chalcogenide-nanocrystals-pt02820nas a2200313 4500008004100000245018800041210006900229260000800298300001600306490000600322520168400328653002302012653001802035653003302053653003202086653002002118653003302138653002202171100002002193700001602213700001702229700001702246700002002263700001902283700002402302700002602326700002402352856013002376 2022 eng d00aFirst-principles investigation of the electrocatalytic reduction of CO2 on zirconium-based single-, double-, and triple-atom catalysts anchored on a graphitic carbon nitride monolayer0 aFirstprinciples investigation of the electrocatalytic reduction  cOCT a15409-154170 v53 a

Conversion of carbon dioxide (CO2) with the help of an appropriate electrocatalyst with high stability, low onset potential, and exceptional selectivity is still one of the great tasks in the electrocatalytic reduction of CO2 to valuable chemicals. Herein, by means of systematic first-principles simulations, we investigate the CO2 reduction reaction (CO2RR) activity of zirconium-based single-, double-, and triple-atom (Zrn@C2N; n = 1-3) catalysts anchored on a graphitic carbon-nitride monolayer. In tune with the Sabatier principle, our results reveal that a moderate CO2 binding is vital for a low onset potential for the CO2RR. Consequently, based on rigorous free energy calculations, the Zr-based single-atom catalyst (SAC) is found to be most effective to convert CO2 to valuable products such as HCOOH and CH3OH. It is worth noting that CO2 reduction to HCOOH is spontaneous via the *HCOO intermediate on Zr1@C2N and involves a low onset potential of -0.23 V with respect to the reversible hydrogen electrode from the *COOH intermediate. Among all the catalysts evaluated computationally, the Zr SAC further reveals the lowest onset potential of -0.89 V for CH3OH formation. The results show that the Zr-based catalysts especially Zr1@C2N are found to effectively suppress the competitive hydrogen evolution reaction and promote the CO2RR. Moreover, all three catalysts exhibit high kinetic and thermal stability with negligible distortion due to which their structures can be retained very well up to 600 K. Thus, the current work may provide effective catalyst-design strategies for enhancing the electrocatalytic CO2RR performance of Zr-based materials.

10aC1 and C2 products10aCO2 reduction10afirst-principles simulations10ahydrogen evolution reaction10aonset potential10asingle-atom catalysts (SACs)10aZrn@C2N catalysts1 aHassan, Afshana1 aAnis, Insha1 aShafi, Sadaf1 aAssad, Assif1 aRasool, Anjumun1 aKhanam, Romana1 aBhat, Gulzar, Ahmad1 aKrishnamurty, Sailaja1 aDar, Manzoor, Ahmad uhttp://library.ncl.res.in/content/first-principles-investigation-electrocatalytic-reduction-co2-zirconium-based-single-double02931nas a2200301 4500008004100000022001400041245018200055210006900237260000900306300001200315490000800327520183100335653003302166653003202199653003002231653003102261653001602292100002502308700002502333700001902358700002002377700002802397700002102425700001902446700001602465700002502481856012302506 2023 eng d a0021-979700aThermally constructed stable Zn-doped NiCoOx-z alloy structures on stainless steel mesh for efficient hydrogen production via overall hydrazine splitting in alkaline electrolyte0 aThermally constructed stable Zndoped NiCoOxz alloy structures on cJUN  a737-7490 v6403 a

Hydrogen has a high energy density of approximately 120 to 140 MJ kg(-1), which is very high compared to other natural energy sources. However, hydrogen generation through electrocatalytic water splitting is a high electricity consumption process due to the sluggish oxygen evolution reaction (OER). As a result, hydrogen generation through hydrazine-assisted water electrolysis has recently been intensively investigated. The hydrazine electrolysis process requires a low potential compared to the water electrolysis process. Despite this, the utilization of direct hydrazine fuel cells (DHFCs) as portable or vehicle power sources necessitates the development of inexpensive , effective anodic hydrazine oxidation catalysts. Here, we prepared oxygen-deficient zinc-doped nickel cobalt oxide (Zn-NiCoOx-z) alloy nanoarrays on stainless steel mesh (SSM) using a hydrothermal synthesis method followed by thermal treatment. Furthermore, the prepared thin films were used as electrocatalysts , the OER and hydrazine oxidation reaction (HzOR) activities were investigated in three-and two-electrode systems. In a three-electrode system, Zn-NiCoOx-z/SSM HzOR requires-0.116 V (vs RHE) potential to achieve a 50 mA cm(-2) current density, which is dramatically lower than the OER potential (1.493 V vs RHE). In a two-electrode system (Zn-NiCoOx-z/SSM(-)IIZn-NiCoOx-z/SSM(+)), the overall hydrazine splitting potential (OHzS) required to reach 50 mA cm(-2) is only 0.700 V, which is dramatically less than the required potential for overall water splitting (OWS). These excellent HzOR results are due to the binder-free oxygen-deficient Zn-NiCoOx-z/ SSM alloy nanoarray, which provides a large number of active sites and improves the wettability of cat-alysts after Zn doping. (C) 2023 Elsevier Inc. All rights reserved.

10aHydrazine Oxidation Reaction10ahydrogen evolution reaction10aOxygen Evolution Reaction10aOxygen-Deficient Materials10aZinc Doping1 aKashale, Anil, Ashok1 aRasal, Akash, Sanjay1 aHsu, Fei-Chien1 aChen, ChangChun1 aKulkarni, Sayali, Nitin1 aChang, Chun, Hao1 aChang, Jia-Yaw1 aLai, Yuekun1 aChen, I., -Wen Peter uhttp://library.ncl.res.in/content/thermally-constructed-stable-zn-doped-nicoox-z-alloy-structures-stainless-steel-mesh01818nas a2200253 4500008004100000022001400041245011500055210006900170260000900239300001200248490000700260520090800267653001701175653002101192653002201213653003201235653002601267653003001293100002101323700003501344700002401379700003101403856013001434 2024 eng d a0360-319900aElectrodeposited Co-Mn-Sn multicomponent alloy as an efficient electrocatalyst for hydrogen evolution reaction0 aElectrodeposited CoMnSn multicomponent alloy as an efficient ele cJAN  a658-6670 v493 a

Despite having exciting material characteristics, the potential of multi-component alloys (MCAs) as electrocatalysts has not been fully realized. In this work, efficient binary and ternary MCA electrocatalysts containing inexpensive metals like Co, Mn and Sn have been prepared via the electrodeposition process. When tested for hydrogen evolution reaction (HER) in an alkaline medium, ternary Co-Mn-Sn alloy displayed enhanced activity with the lowest overpotential of 136 mV, a Tafel slope of 111 mV dec 1 and a very low charge transfer resistance, making it superior to the binary alloys (Co-Mn and Co-Sn), or the single metal catalysts (Co, Mn and Sn). The ternary alloy also displayed high electro-chemical and structural stability, making it a viable electrocatalyst for the hydrogen economy.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

10aClean energy10aelectrocatalysis10aElectrodeposition10ahydrogen evolution reaction10aMulti-component alloy10aNon-platinum group metals1 aChandran, Athira1 aKarumuthil, Subash, Cherumanni1 aSingh, Ashutosh, K.1 aPrasad, Bhagavatula, L. V. uhttp://library.ncl.res.in/content/electrodeposited-co-mn-sn-multicomponent-alloy-efficient-electrocatalyst-hydrogen-evolution