H2O and H2 interaction with ZnO surfaces: A MNDO, AM1, and PM3 theoretical study with large cluster models

Abstract

mWe investigated the adsorption and heterolytic dissociation of H 2 0 and H2 molecules on a (ZnO)*? cluster corresponding to ZnO (OOOl), (OOOl), and (lOi0) surfaces using MNDO, AM^, and PM3 semiempirical procedures. The geometry of the adsorbed molecule has been optimized in order to analyze binding energies, charge transfer, and preferential sites of interaction. The adsorbed species interact most strongly when it is bonded to the twofold coordinated zinc atom of the cluster surface. The interaction of the H 2 0 molecule with the surface of ZnO has a charge transfer from H 2 0 to the surface ranging between 0.17 and 0.27 au. The neighboring atoms of the surface are the main receptors during the process of charge transfer. Our results indicate that there is a weak bonding of the hydrogen atom from OH with the oxygen surface atom that could produce the O--H....O band. The interaction of the H2 molecule with the surface is generally weak and only the PM3 method yields a strong binding energy for this interaction. There is a charge transfer from the H2 molecule to the surface. The chemisorption of H on oxygen atom of the surface transfer charge from the surface to the H. We also calculated the vibrational analyses for these interactions on ZnO surface and compared our results with available experimental data.

Análise teórica da interação de CO, CO2 e NH3 com ZnO

“…Neste trabalho selecionou-se os modelos de grande porte, (ZnO) 22 e (ZnO) 60 , Figura 1, para descrever a superfície do óxido de zinco [40][41][42]61 a fim de estudar a interação de CO, CO 2 e NH 3 com a superfície (0001) do ZnO. A simulação foi desenvolvida utilizando o método semi-empírico AM1, implementado no programa MOPAC 6.0 62 , para a otimização dos parâmetros geométricos.…”

“…Moléculas que interagem com superfícies de ZnO têm sido objeto de diversos estudos teóricos [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] 57 . A seguir, são analisadas as energias de ligação (EL), densidade de estados (DOS), transferência de carga, energias dos orbitais SCF e parâmetros geométricos otimizados, através de metodologia ab initio Hartree-Fock com o conjunto de funções de base 3-21G*.…”

ZnO nanowires: chemical growth, electrodeposition, and application to intracellular nano‐sensors

“…These sensors can be combined to produce a greater level of accuracy from a single proton or hydroxyl. The pH response of ZnO polar and nonpolar surfaces has been explained in terms of the formation of hydroxyl groups that lead to a pH-dependent net surface charge with a resulting change in voltage at the electrode/liquid interface [70][71][72][73]. The principle of the ZnO nanowire electrochemical potential pH sensor shows that when a solid is emerged in a polar solvent or an electrolyte solution, a surface charge will be developed.…”

First principles investigation of oxygen adsorptions on hydrogen–terminated ZnO graphene-like nanosheets

“…The crystal faces of zinc oxide (ZnO) have been studied by several experimental and theoretical techniques on adsorptions of H 2 [1][2][3][4][5], CO [6], H 2 O [7][8][9], CO 2 [10], NH 3 [11], NO [12], NO 2 [12,13], SO 2 [13] and N 2 O [14]. ZnO materials have excellent performance in optics, electronics, photoelectronics [1] and piezoelectricity [2].…”

“…ZnO materials have excellent performance in optics, electronics, photoelectronics [1] and piezoelectricity [2]. It can also be used as transducers and sensors due to their strong piezoelectricity.…”