Pooja Basera

All Publications

• 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