Pooja Basera

All Publications

• The Role of Cu3+ in the Oxygen Evolution Activity of Copper Oxides. Journal of the American Chemical Society Basera, P., Zhao, Y., Garcia-Esparza, A. T., Babbe, F., Bothra, N., Vinson, J., Sokaras, D., Yano, J., Boettcher, S. W., Bajdich, M. 2025

  Abstract

  Cu-based oxides and hydroxides represent an important class of materials from a catalytic and corrosion perspective. In this study, we investigate the formation of bulk and surface Cu3+ species that are stable under water oxidation catalysis in alkaline media. So far, no direct evidence existed for the presence of hydroxides (CuOOH) or oxides, which were primarily proposed by theory. This work directly places CuOOH in the oxygen evolution reaction (OER) Pourbaix stability region with a calculated free energy of -208.68 kJ/mol, necessitating a revision of known Cu-H2O phase diagrams. We also predict that the active sites of CuOOH for the OER are consistent with a bridge O* site between the two Cu3+ atoms with onset at ≥1.6 V vs the reversible hydrogen electrode (RHE), aligning with experimentally observed Cu2+/3+ oxidation waves in cyclic voltammetry of Fe-free and Fe-spiked copper in alkaline media. Trace amounts of Fe (2 μg/mL (ppm) to 5 μg/mL) in the solution measurably enhance the catalytic activity of the OER, likely due to the adsorption of Fe species that serve as the active sites . Importantly, modulation excitation X-ray absorption spectroscopy (ME-XAS) of a Cu thin-film electrode shows a distinct Cu3+ fingerprint under OER conditions at 1.8 V vs RHE. Additionally, in situ Raman spectroscopy of polycrystalline Cu in 0.1 mol/L (M) KOH revealed features consistent with those calculated for CuOOH in addition to CuO. Overall, this work provides direct evidence of bulk electrochemical Cu3+ species under OER conditions and expands our longstanding understanding of the oxidation mechanism and catalytic activity of copper.

  View details for DOI 10.1021/jacs.4c18147

  View details for PubMedID 40311110

• Rationalizing the Superior Catalytic Efficiency of Nickel Nitride vs Nickel Sulfide for Alkaline Hydrogen Evolution Reaction from Bubble Dynamics Study and Density Functional Theory (DFT) Calculations ACS CATALYSIS Tyagi, C., Basera, P., Lagrost, C., Bouquet, V., Tessier, F., Jullien, M., Fabre, B. 2025

  View details for DOI 10.1021/acscatal.4c05777

  View details for Web of Science ID 001425868500001

• Bidentate Lewis Base Ligand-Mediated Surface Stabilization and Modulation of the Electronic Structure of CsPbBr3 Perovskite Nanocrystals. Journal of the American Chemical Society Hassan, M. S., Basera, P., Khan, B., Portniagin, A. S., Vighnesh, K., Wu, Y., Rusanov, D. A., Babak, M., He, J. H., Bajdich, M., Rogach, A. L. 2024

  Abstract

  The desorption of conventional ligands from the surface of halide perovskite nanocrystals (NCs) often causes their structural instability and deterioration of the optoelectronic properties. To address this challenge, we present an approach of using a bidentate Lewis base ligand, namely, 1,4-bis(diphenylphosphino)butane (DBPP), for the synthesis of CsPbBr3 NCs. The phosphine group of DBPP has a strong interaction with the PbBr2 precursor, forming a highly crystalline intermediate complex during the reaction. In the presence of oleic acid, the uncoordinated phosphine group of DBPP is converted into the phosphonium cation, which strongly binds to the surface bromide of the formed CsPbBr3 NCs through hydrogen bonding. Density functional theory calculations suggest that DBPP can strongly bind to the undercoordinated lead and surface bromide ions of CsPbBr3 NCs through its unprotonated and protonated phosphine groups, respectively. The robust binding of DBPP to the surface of perovskite NCs helps to preserve their structural integrity under various environmental stresses. Moreover, the electron density and energy levels are regulated in DBPP-capped CsPbBr3 NCs by the donation of electrons from the ligands to the NCs, resulting in their improved photocatalytic CO2 reduction performance. Our study highlights the potential of using bidentate ligands to stabilize the surface of perovskite NCs and modulate their optical and electronic properties.

  View details for DOI 10.1021/jacs.4c13724

  View details for PubMedID 39705016

• Trace Ru Incorporation Boosted Co2P Nanorods for Superior Water Electrolysis and Substrate-Paired Electrolysis Toward Value-Added Chemicals in Alkaline Medium. Small (Weinheim an der Bergstrasse, Germany) Ganguly, S., Basera, P., Ahmed, S., Saha, S., Dutta, A., Loha, C., Ghosh, S. 2024: e2405056

  Abstract

  Electro-valorization of biomass-derived chemicals has ensured sustainable production of value-added products, an effective approach for reducing carbon footprint, through renewable energy. Electrochemical oxidation and reduction reactions in aqueous media using H2O as a potential source for active hydrogenated and oxygenated species fulfill the purpose. In this study, Ru─Co2P nanorods are explored as a bifunctional electrocatalyst toward valorization of Organics at basic media. The in-situ electrogenerated Co3+ and Co4+ species act as active oxidants toward product selectivity. An overpotential of 68 mV is found for hydrogen evolution reaction (1 m NaOH) with Ru─Co2P. Further, used as cathode, Ru─Co2P effectively reduces furfuraldehyde to furfuryl alcohol and p-nitrophenol to p-aminophenol. Ru doping enables ease of formation of active species both for reduction and oxidation, faster charge transfer between catalyst to absorbates. Density Functional Theory calculation establishes Ru incorporation in Co2P surface results in enhanced adsorption of substrates. Ru doping modulates the electronic structure of Co2P which changes the density of states resulting in faster water dissociation and water splitting. To reach 10 mA cm-2 current density only 1.6 V is required for water electrolysis, whereas 1.4 V is enough for substrate-paired electrolysis with simultaneous oxidation of benzyl alcohol and reduction of p-nitro phenol.

  View details for DOI 10.1002/smll.202405056

  View details for PubMedID 39449551

• Oxidizing Role of Cu Cocatalysts in Unassisted Photocatalytic CO2Reduction Using p-GaN/Al2O3/Au/Cu Heterostructures. ACS nano Zoric, M. R., Basera, P., Palmer, L. D., Aitbekova, A., Powers-Riggs, N., Lim, H., Hu, W., Garcia-Esparza, A. T., Sarker, H., Abild-Pedersen, F., Atwater, H. A., Cushing, S. K., Bajdich, M., Cordones, A. A. 2024

  Abstract

  Photocatalytic CO2 reduction to CO under unassisted (unbiased) conditions was recently demonstrated using heterostructure catalysts that combine p-type GaN with plasmonic Au nanoparticles and Cu nanoparticles as cocatalysts (p-GaN/Al2O3/Au/Cu). Here, we investigate the mechanistic role of Cu in p-GaN/Al2O3/Au/Cu under unassisted photocatalytic operating conditions using Cu K-edge X-ray absorption spectroscopy and first-principles calculations. Upon exposure to gas-phase CO2 and H2O vapor reaction conditions, the composition of the Cu nanoparticles is identified as a mixture of CuI and CuII oxide, hydroxide, and carbonate compounds without metallic Cu. These composition changes, indicating oxidative conditions, are rationalized by bulk Pourbaix thermodynamics. Under photocatalytic operating conditions with visible light excitation of the plasmonic Au nanoparticles, further oxidation of CuI to CuII is observed, indicating light-driven hole transfer from Au-to-Cu. This observation is supported by the calculated band alignments of the oxidized Cu compositions with plasmonic Au particles, where light-driven hole transfer from Au-to-Cu is found to be thermodynamically favored. These findings demonstrate that under unassisted (unbiased) gas-phase reaction conditions, Cu is found in carbonate-rich oxidized compositions rather than metallic Cu. These species then act as the active cocatalyst and play an oxidative rather than a reductive role in catalysis when coupled with plasmonic Au particles for light absorption, possibly opening an additional channel for water oxidation in this system.

  View details for DOI 10.1021/acsnano.4c02088

  View details for PubMedID 39037113

• A-Site Modulation of Co-Ir Based Double Perovskite Oxides (A₂CoIrO₆, A = Sr, Nd, Pr, and Sm) for Maximization of Water Oxidation and Hybrid Electrolysis Derived Isopropanol Upconversion in Acid Medium ACS SUSTAINABLE CHEMISTRY & ENGINEERING Ganguly, S., Datta, R., Basera, P., De, S., Mistry, K., Loha, C., Ghosh, S. 2023; 12 (2): 849-859

  View details for DOI 10.1021/acssuschemeng.3c05753

  View details for Web of Science ID 001143583300001