Ti3C2-MXene/NiO Nanocomposites-Decorated CsPbI3 Perovskite Active Materials under UV-Light Irradiation for the Enhancement of Crystal-Violet Dye Photodegradation

Abstract

Ti₃C₂-MXene material, known for its strong electronic conductivity and optical properties, has emerged as a promising alternative to noble metals as a cocatalyst for the development of efficient photocatalysts used in environmental cleanup. In this study, we investigated the photodegradation of crystal-violet (CV) dye when exposed to UV light using a newly developed photocatalyst known as Ti₃C₂-MXene/NiO nanocomposite-decorated CsPbI₃ perovskite, which was synthesized through a hydrothermal method. Our research investigation into the structural, morphological, and optical characteristics of the Ti₃C₂-MXene/NiO/CsPbI₃ composite using techniques such as FTIR, XRD, TEM, SEM-EDS mapping, XPS, UV-Vis, and PL spectroscopy. The photocatalytic efficacy of the Ti₃C₂-MXene/NiO/CsPbI₃ composite was assessed by evaluating its ability to degrade CV dye in an aqueous solution under UV-light irradiation. Remarkably, the Ti₃C₂-MXene/NiO/CsPbI₃ composite displayed a significant improvement in both the degradation rate and stability of CV dye when compared to the Ti₃C₂-MXene/NiO nanocomposite and CsPbI₃ perovskite materials. Furthermore, the UV-visible absorption spectrum of the Ti₃C₂-MXene/NiO/CsPbI₃ composite demonstrated a reduced band gap of 2.41 eV, which is lower than that of Ti₃C₂-MXene/NiO (3.10 eV) and Ti₃C₂-MXene (1.60 eV). In practical terms, the Ti₃C₂-MXene/NiO/CsPbI₃ composite achieved an impressive 92.8% degradation of CV dye within 90 min of UV light exposure. We also confirmed the significant role of photogenerated holes and radicals in the CV dye removal process through radical scavenger trapping experiments. Based on our findings, we proposed a plausible photocatalytic mechanism for the Ti₃C₂-MXene/NiO/CsPbI₃ composite. This research may open up new avenues for the development of cost-effective and high-performance MXene-based perovskite photocatalysts, utilizing abundant and sustainable materials for environmental remediation.

Keywords: NiO; Ti3C2-MXene; UV-light irradiation; crystal violet; perovskite; photodegradation.

Figure 1

(A) FTIR spectra and (B) XRD pattern of (a) Ti₃C₂-MXene nanosheets, (b) NiO, (c) Ti₃C₂-MXene/NiO, (d) CsPbI₃, and (e) Ti₃C₂-MXene/NiO/CsPbI₃ composites.

Figure 2

TEM images of (a,b) Ti₃C₂-MXene nanosheets and (c) the corresponding HRTEM image, TEM images of (d) Ti₃C₂-MXene/NiO and (e–g) the corresponding HRTEM image, and TEM images of (h) Ti₃C₂-MXene/NiO/CsPbI₃ composites and (i–k) the corresponding HRTEM image.

Figure 3

FE-SEM images of (a,b) Ti₃C₂-MXene nanosheets, (c) NiO, (d,e) Ti₃C₂-MXene/NiO, (f) CsPbI3, and (g–i) Ti₃C₂-MXene/NiO/CsPbI₃ composites.

Figure 4

FE-SEM image and the corresponding EDS elemental mapping of Ti₃C₂-MXene/NiO/CsPbI₃ composites.

Figure 5

(a) XPS survey scan spectrum of Ti₃C₂-MXene/NiO and high-resolution XPS spectra of elements (b) Ti2p, (c) C1s, (d) Ni2p, (e) O1s, (f) Cs3d, (g) Pb4f, and (h) I3d states for Ti₃C₂-MXene/NiO. (Black line; fitting and violet line; background).

Figure 6

(a) UV–Visible absorption spectra of Ti₃C₂-MXene nanosheets, Ti₃C₂-MXene/NiO, and Ti₃C₂-MXene/NiO/CsPbI₃ composites and Tauc plot of (b) Ti₃C₂-MXene nanosheets, (c) Ti₃C₂-MXene/NiO, and (d) Ti₃C₂-MXene/NiO/CsPbI₃ composites from UV–Visible absorption spectroscopy.

Figure 7

PL spectra of Ti₃C₂-MXene nanosheets, NiO, Ti₃C₂-MXene/NiO, and Ti₃C₂-MXene/NiO/CsPbI₃ composites.

Figure 8

(a) Electrochemical impedance spectra and (b) photocurrent response of Ti₃C₂-MXene nanosheets, Ti₃C₂-MXene/NiO, and Ti₃C₂-MXene/NiO/CsPbI₃ composites.

Figure 9

Absorption spectra of CV-dye photodegradation over, (a) Ti₃C₂-MXene nanosheets, (b) Ti₃C₂-MXene/NiO, and (c) Ti₃C₂-MXene/NiO/CsPbI₃ composites.

Figure 10

Degradation curves profiles of CV dye over Ti₃C₂-MXene nanosheets, Ti₃C₂-MXene/NiO, and Ti₃C₂-MXene/NiO/CsPbI₃ composites, (a) the degradation rate, (b) linear kinetic, (c) rate constant, and (d) percentage degradation of dye.

Figure 11

(a) Effect of different scavengers and (b) cyclic stability performance of Ti₃C₂-MXene/NiO/CsPbI₃ composites in the photocatalytic removal of CV.

Figure 12

Schematic illustration of the proposed mechanism for photocatalytic degradation of CV dye using Ti₃C₂-MXene/NiO/CsPbI₃ composites photocatalyst.