High potential and robust ternary LaFeO3/CdS/carbon quantum dots nanocomposite for photocatalytic H2 evolution under sunlight illumination

Saikumar Manchala; Ambedkar Gandamalla; Navakoteswara Rao Vempuluru; Shankar Muthukonda Venkatakrishnan; Vishnu Shanker

doi:10.1016/j.jcis.2020.08.125

High potential and robust ternary LaFeO₃/CdS/carbon quantum dots nanocomposite for photocatalytic H₂ evolution under sunlight illumination

J Colloid Interface Sci. 2021 Feb 1:583:255-266. doi: 10.1016/j.jcis.2020.08.125. Epub 2020 Sep 15.

Authors

Saikumar Manchala¹, Ambedkar Gandamalla², Navakoteswara Rao Vempuluru³, Shankar Muthukonda Venkatakrishnan³, Vishnu Shanker⁴

Affiliations

¹ Department of Chemistry, National Institute of Technology, Warangal 506004, Telangana, India; Centre for Advanced Materials, National Institute of Technology, Warangal 506004, Telangana, India; Department of Chemistry, Indian Insititute of Technology, Hauz Khas, New Delhi 110016, India.
² Department of Chemistry, National Institute of Technology, Warangal 506004, Telangana, India; Centre for Advanced Materials, National Institute of Technology, Warangal 506004, Telangana, India.
³ Nano Catalysis and Solar Fuels Research Laboratory, Department of Materials Science and Nanotechnology, Yogi Vemana University, Vemanapuram, Kadapa 516005, Andhra Pradesh, India.
⁴ Department of Chemistry, National Institute of Technology, Warangal 506004, Telangana, India; Centre for Advanced Materials, National Institute of Technology, Warangal 506004, Telangana, India. Electronic address: vishnu@nitw.ac.in.

PMID: 33002697
DOI: 10.1016/j.jcis.2020.08.125

Abstract

Exploitation of the novel, robust, and advanced photocatalytic systems with high efficiency is the present demand for clean, green, and sustainable energy production. Carbon quantum dots (CQDs) have attracted tremendous interest in efficient H₂ evolution from photocatalysis due to its remarkable visible-light harvesting and electron transport properties. Here, for the first time, a smart ternary nanocomposite comprises encapsulated CQDs with LaFeO₃ spherical nanoparticles and CdS nanorods is synthesized by a simple hydrothermal procedure for the efficient photocatalytic H₂ evolution under sunlight illumination. PXRD, FT-IR, FE-SEM, TEM, and XPS studies are performed to ensure the successful fabrication of ternary LaFeO₃/CdS/CQD nanocomposite. The efficient H₂ evolution rate (HER) of 25,302 μmol h^-1 g_cat^-1 is achieved for LaFeO₃/CdS/CQD nanocomposite, which is 602.4, 2.6, 29.8, 2.0 and 1.1 times higher than that of pristine LaFeO₃, pristine CdS, and composites such as LaFeO₃/CdS, LaFeO₃/CQD, and CdS/CQD. Photocurrent and lifetime PL studies reveal, encapsulation of CQDs with the LaFeO₃/CdS heterojunction can facilitate easy and efficient separation of photo-generated excitons. Altogether the fabrication of CQDs provides an ideal avenue for the development of high potential advanced photocatalytic systems for sustainable H₂ production with remarkable efficiencies.

Keywords: Carbon quantum dots; Inter-facial electron transfer; LaFeO(3)/CdS; Photocatalytic H(2) evolution; Synergetic effect; Ternary nanocomposite.