Electrochemical Deposition of Mn:ZnO Films under Hydrothermal Conditions

Abstract

This study demonstrated the electrochemical deposition of Mn-doped ZnO films under hydrothermal conditions at 130 • C in 50% v/v DMSO-H 2 O mixture. X-ray diffraction analysis showed that the deposition of the ZnO structures was along (002) direction. However, the presence of Mn 2+ affected the thickness of ZnO structures and we believe that the interaction of Mn 2+ with the nonpolar surface of ZnO restricts lateral growth. Mn appears in the mixed oxide state in ZnO lattice. The photoluminescence spectra of the films show only UV emission indicating high crystal quality. The blueshift of the UV emission is observed after the introduction of Mn impurity into the ZnO lattice. The surface morphology, lattice structure, Mn content, chemical binding characteristics, and optical properties of the deposits were examined by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and photoluminescence spectroscopy, respectively.

Hydrothermal–electrochemical growth of heterogeneous ZnO: Co films

“…1. A deposition bath containing only 50 mM Zn(NO 3 ) 2 in 1:1 DMSO: H 2 O mixture gives rise to the formation of thin platelets with about 1-2-lm-sized edges as shown in our previous study (Yilmaz and Unal 2013). Similar morphology was observed for the film grown from the bath containing Zn(NO 3 ) 2 and Co(NO 3 ) 2 with a [Co(II)]: [Zn(II)] ratio of 0.2.…”

“…Effect of additives is significantly influenced by high-temperature electrodeposition with each cation and anion behaving differently. It has been presented that by adjusting [MnCl 2 ] in the deposition bath, diameters of ZnO rods can be tuned by HED (Yilmaz and Unal 2013). In the following study, we have shown that besides precursor concentration, identities of the additive metal cation and counter ion in the deposition solution are important to produce ZnO particles with various morphologies.…”

“…A mass of DMSO is most likely absorbed on to the polar basal plane of ZnO inhibiting the absorption of additional growth units on (0001) plane. As a result, growth proceeds along six symmetric nonpolar planes, and ZnO platelets were obtained in the absence of Co(II) ions in DMSO-H 2 O mixture (Yilmaz and Unal 2013). Besides morphological control, DMSO undergoes hydrolysis in aqueous solutions and also contributes toward increasing the OH -ion concentration according to the following equation (Rodríguez-Gattorno et al 2003):…”

“…HED primarily affects the growth kinetics; hence, crystallinity and morphology of deposited particles (Yilmaz and Unal 2015). Furthermore, by the synergistic effect of the growth-modifier molecules and HED, metal oxide particles with various shapes including spherical-, rhombohedral-, and platelet-like particles can be obtained (Yilmaz and Unal 2013;Yilmaz and Unal 2016;Yilmaz and Unal 2014). Effect of additives is significantly influenced by high-temperature electrodeposition with each cation and anion behaving differently.…”

Electrochemical-Hydrothermal Synthesis of Manganese Oxide Films as Electrodes for Electrochemical Capacitors

“…The method combines one step production of oriented ceramics with high growth rate [18]. Deposition of various ceramics and double oxides such as ZnO [19][20][21][22], LiCoO 2 [23], and LiNiO 2 [24] with this technique were reported previously. Regarding manganese oxides, Hill et al conducted systematic studies on hydrothermalelectrochemical deposition of manganese oxides (mainly MnO 2 ) [25][26][27][28].…”