Insight into the Growth Mechanism of Mixed Phase CZTS and the Photocatalytic Performance

Abstract

In this work, CZTS particles with a mixed phase of wurtzite and kesterite were synthesized by the solvothermal method. The time-dependent XRD patterns, Raman spectra, SEM, and EDS analysis were employed to study the growth mechanism of CZTS. The results revealed that the formation of CZTS started from the nucleation of monoclinic Cu7S4 seeds, followed by the successive incorporation of Zn2+ and Sn4+ ions. Additionally, the diffusion of Zn2+ into Cu7S4 crystal lattice is much faster than that of Sn4+. With increasing time, CZTS undergoes a phase transformation from metastable wurtzite to steady kesterite. The morphology of CZTS tends to change from spherical-like to flower-like architecture. The mixed-phase CZTS with a bandgap of 1.5 eV exhibited strong visible light absorption, good capability for photoelectric conversion, and suitable band alignment, which makes it capable to produce H2 production and degrade RhB under simulated solar illumination.

Anion-Directed Synthesis of Core–Shell and Janus Hybrid Nanostructures

“…Consistent with HRTEM, the major lattice spacings in the FFT pattern match kesterite CZTS (Figure g). XRD spectra of Ag 2 S-CZTS Janus nanoparticles have (Figure i) peaks at 2θ = 34.38° (−121), 34.70° (022), 36.80° (121), and 37.71° (−103), matching with the monoclinic crystal phase (JCPDS# 00-014-0072) of Ag 2 S. Weak peaks are also observed at 40.73 and 43.40°, attributed to the 031 and 200 planes of Ag 2 S. The intense CZTS peaks (JCPDS# 00-026-0575) observed at 28.53° (112), 47.33° (220), 56.17° (312), and 76.44° (332) correspond to those of the kesterite phase. , The type of capping ligands, reactivity of the precursors, and their interaction with other metal cations are known to strongly influence the crystallographic phase of CZTS. − The formation of binary sulfide (Cu 2– X S) nuclei determines the formation of wurtzite or kesterite phase. Sulfur precursors with high reactivity such as elemental sulfur generally result in the form of kesterite phase.…”

A Convenient In Situ Preparation of Cu2ZnSnS4–Anatase Hybrid Nanocomposite for Photocatalysis/Photoelectrochemical Water-Splitting Hydrogen Production

“…In CZTS, two strong peaks are located around 1045.0 eV (Zn 2p 1/2 ) and 1021.8 eV (Zn 2p 3/2 ), separated by 23.2 eV. In CZTS–A 5 , the intense peak is concentrated at 1045.3 eV (Zn 2p 1/2 ) and 1022.1 eV (Zn 2p 3/2 ), maintaining the same splitting value of 23.2 eV, indicating the presence of the Zn 2+ oxidation state [ 32 , 33 , 35 ]. The appearance of Zn 2+ may be related to the conductivity and light absorption characteristics of the material.…”

“…In Equation (2), which illustrates the Tauc plot, α signifies the direct light absorption coefficient, h is Planck's constant, ν represents the frequency of incident light, A is proportionality constant, and E g denotes the band gap energy of the semiconductor photocatalyst [35]. The band gap can be estimated based on the Tauc plot (Equation ( 3)).…”

Solvothermal Synthesis of Cu2ZnSnSe4 Nanoparticles and Their Visible-Light-Driven Photocatalytic Activity

“…Recently, CZTSe nanocrystals have been prepared by different wet chemical solutionbased routes, i.e., high temperature arrested precipitation, solvothermal, hydrothermal, colloidal hot injection route, automated continuous-flow process, microwave-assisted, and others [1,6,12,[36][37][38][39][40][41]. Among them, as an important method for wet chemistry, featuring low temperature, simplicity, good yield, convenient handling, inexpensive equipment, and controllable uniform particle size and regular morphology, the solvothermal method has been widely employed for the preparation of quaternary CZTSe nanocrystalline samples [1,6,36,37,[40][41][42][43][44][45][46][47]. Moreover, in the solvothermal method, the growth conditions, such as solvent, temperature, duration, and precursor sources, can be varied to tune the phase, morphology, and shape of the CZTSe particles [36,43,46,47].…”

“…Among them, as an important method for wet chemistry, featuring low temperature, simplicity, good yield, convenient handling, inexpensive equipment, and controllable uniform particle size and regular morphology, the solvothermal method has been widely employed for the preparation of quaternary CZTSe nanocrystalline samples [1,6,36,37,[40][41][42][43][44][45][46][47]. Moreover, in the solvothermal method, the growth conditions, such as solvent, temperature, duration, and precursor sources, can be varied to tune the phase, morphology, and shape of the CZTSe particles [36,43,46,47]. In the present study, the solvothermal synthesis of CZTSe nanoparticles was performed using ethylenediamine as the solvent.…”