Zirconium-Doped Zinc Oxide Nanoparticles: Synthesis, Structural Characteristics, Physicochemical Properties and Emerging Applications

Abstract

Zirconium-doped zinc oxide (Zr–ZnO) nanoparticles have emerged as promising
multifunctional semiconductor nanomaterials because zirconium incorporation can modify
the structural, optical, electrical, surface and catalytic characteristics of ZnO. Zinc oxide
possesses a wide direct band gap, high exciton binding energy, chemical stability and diverse
nanoscale morphologies, making it suitable for photocatalysis, antimicrobial materials,
sensing, optoelectronics and environmental applications. However, the functional
performance of pristine ZnO is influenced by charge-carrier recombination, defect
concentration, particle aggregation and limited visible-light utilization. Elemental doping
provides an effective strategy for modifying these characteristics. Among different dopants,
zirconium is particularly interesting because of its ability to alter lattice structure, defect
chemistry, carrier behavior and surface properties. This article reviews the reported
synthesis strategies, structural characteristics, physicochemical properties and emerging
applications of Zr-doped ZnO nanoparticles. Sol–gel, precipitation, hydrothermal and
combustion-assisted approaches are discussed in relation to particle size, crystallinity,
morphology and dopant incorporation. X-ray diffraction, electron microscopy, energy-
dispersive spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, X-
ray photoelectron spectroscopy, UV–visible spectroscopy and photoluminescence are
considered as complementary characterization approaches. Particular attention is given to
concentration-dependent changes in crystallite size, lattice parameters, optical band gap,
defect states, surface characteristics, electrochemical response and photocatalytic
performance. Published evidence indicates that controlled Zr incorporation can retain the
hexagonal wurtzite structure while modifying the physicochemical characteristics of ZnO.
Zr–ZnO nanoparticles have demonstrated potential in photocatalytic water treatment,
antibacterial materials and electrochemical sensing, while related Zr-doped ZnO
nanostructures have also been investigated for transparent conducting and photovoltaic
applications. The review identifies current limitations related to dopant distribution,
concentration optimization, reproducibility, scalability and safety and proposes future
research directions for application-specific Zr–ZnO nanomaterials.