Improved photocatalytic activity of TiO2 nanoparticles through nitrogen and phosphorus co-doped carbon quantum dots: an experimental and theoretical study

Yashwanth, HJ and Rondiya, SR and Dzade, NY and Hoye, RLZ and Choudhary, RJ and Phase, DM and Dhole, SD and Hareesh, K (2022) Improved photocatalytic activity of TiO2 nanoparticles through nitrogen and phosphorus co-doped carbon quantum dots: an experimental and theoretical study. In: Physical Chemistry Chemical Physics .

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Abstract

In this work, we develop a photocatalyst wherein nitrogen and phosphorus co-doped carbon quantum dots are scaffolded onto TiO2 nanoparticles (NPCQD/TiO2), denoted as NPCT hereafter. The developed NPCT photocatalyst exhibits an enhanced visible light photocatalytic hydrogen production of 533 μmol h−1 g−1 compared to nitrogen doped CQD/TiO2 (478 μmol h−1 g−1), phosphorus doped CQD/TiO2 (451 μmol h−1 g−1) and pure CQD/TiO2 (427 μmol h−1 g−1) photocatalysts. The enhanced photocatalytic activity of the NPCT photocatalyst is attributed to the excellent synergy between NPCQDs and TiO2 nanoparticles, which results in the creation of virtual energy levels, a decrease in work function and suppressed recombination rates, thereby increasing the lifetime of photogenerated electrons. A detailed mechanism is proposed for the enhancement in visible light hydrogen production by the NPCT photocatalyst from the experimental results, Mott-Schottky plots and ultraviolet photoelectron spectroscopy results. Further, first-principles density functional theory (DFT) simulations are carried out which predict the decrease in the work function and band gap, and the increase in the density of states of NPCT as the factors responsible for the observed enhancement in visible light photocatalytic hydrogen production.

Item Type:	Journal Article
Publication:	Physical Chemistry Chemical Physics
Publisher:	Royal Society of Chemistry
Additional Information:	The copyright for this article belongs to The Royal Society of Chemistry.
Keywords:	Carbon; Density functional theory; Doping (additives); Energy gap; Hydrogen production; Light; Nanocrystals; Nitrogen; Phosphorus; Photocatalytic activity; Semiconductor quantum dots; TiO2 nanoparticles; Work function, Carbon quantum dots; Co-doped; Doped carbons; Nitrogen and phosphorus; Nitrogen-doped; Phosphorus-doped; Photocatalytic activities; Photocatalytic hydrogen production; Theoretical study; Visible light, Titanium dioxide
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	14 Jul 2022 10:21
Last Modified:	14 Jul 2022 10:21
URI:	https://eprints.iisc.ac.in/id/eprint/74423

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