Fabrication of High Surface Area Microporous ZnO from ZnO/Carbon Sacrificial Composite Monolith Template.

Kunal Mondal,Srujan Singh,Ashutosh Sharma,Monsur Islam

doi:10.3390/mi13020335

Abstract

Fabrication of porous materials from the standard sacrificial template method allows metal oxide nanostructures to be produced and have several applications in energy, filtration and constructing sensing devices. However, the low surface area of these nanostructures is a significant drawback for most applications. Here, we report the synthesis of ZnO/carbon composite monoliths in which carbon is used as a sacrificial template to produce zinc oxide (ZnO) porous nanostructures with a high specific surface area. The synthesized porous oxides of ZnO with a specific surface area of 78 m2/g are at least one order of magnitude higher than that of the ZnO nanotubes reported in the literature. The crucial point to achieving this remarkable result was the usage of a novel ZnO/carbon template where the carbon template was removed by simple heating in the air. As a high surface area porous nanostructured ZnO, these synthesized materials can be useful in various applications including catalysis, photocatalysis, separation, sensing, solar energy harvest and Zn-ion battery and as supercapacitors for energy storage.

Highlights

The development of nanostructures of oxide materials with a high surface area to volume ratio with enough stability is vital for many applications needing improved surface chemistry [1,2,3,4,5,6,7,8,9,10,11,12,13,14]
Using carbon as a sacrificial template, we carried out detailed control experiments to fabricate porous zinc oxide (ZnO) nanostructures and gain an understanding of the critical parameters for nanopore formation. Using these methods and understanding, we showed that it is possible to synthesize high BET surface area microporous ZnO nanostructures from ZnO/carbon composite monoliths
Carbonization of the starting material ZnCl2 /RF monolith obtained through the sol-gel process resulted in a composite material featuring Zn and ZnO embedded within the carbon matrix

Summary

Introduction

The development of nanostructures of oxide materials with a high surface area to volume ratio with enough stability is vital for many applications needing improved surface chemistry [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. The unique microstructures of those porous materials have engrossed considerable attention as a functional material owing to their variety and better performance during applications in the area of catalysis [17], photocatalysis [18], separation [19], adsorption [20], energy storage and conversion [21], and sensing to physicochemical devices [22,23,24] in recent years These materials are usually characterized for their porosity at macro-, meso-, and microscale, uniformity of pores, hierarchy and interconnection between each level of porosity, large accessible high surface areas, low density and excellent accommodation capability of other nanomaterials into the pore volumes, which enables the easy transport of ion/electron/reactant and the diffusion of mass, exposing boundless significance in applications requiring high accessible surface for reactions such as the energy density, rate capacity and cycling life in energy storage and modulation of electronic activities for sensing [25,26]. Porous materials can improve the structural stability of the electrode materials for energy storage and sensor devices for their increasing cyclic life, owing to the large porous space and the interconnection of pores at various micro and nanoscopic length scales, which can accommodate not 4.0/).

Methods

Results

Discussion

Conclusion