Temperature-mediated phase transformation, pore geometry and pore hysteresis transformation of borohydride derived in-born porous zirconium hydroxide nanopowders.

Nadiya B Nayak,Bibhuti B Nayak

doi:10.1038/srep26404

Abstract

Development of in-born porous nature of zirconium hydroxide nanopowders through a facile hydrogen (H2) gas-bubbles assisted borohydride synthesis route using sodium borohydride (NaBH4) and novel information on the temperature-mediated phase transformation, pore geometry as well as pore hysteresis transformation of in-born porous zirconium hydroxide nanopowders with the help of X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) isotherm and Transmission Electron Microscopy (TEM) images are the main theme of this research work. Without any surfactants or pore forming agents, the borohydride derived amorphous nature of porous powders was stable up to 500 °C and then the seed crystals start to develop within the loose amorphous matrix and trapping the inter-particulate voids, which led to develop the porous nature of tetragonal zirconium oxide at 600 °C and further sustain this porous nature as well as tetragonal phase of zirconium oxide up to 800 °C. The novel hydrogen (H2) gas-bubbles assisted borohydride synthesis route led to develop thermally stable porous zirconium hydroxide/oxide nanopowders with an adequate pore size, pore volume, and surface area and thus these porous materials are further suggested for promising use in different areas of applications.

Highlights

Was applicable for catalysis application[24]
The formation of B(OH)4− ions in solution helps to form a precipitate form of zirconium hydroxide [Zr(OH)4] nuclei and the H2 gases generated in the precursor solution were released as gas-bubbles, which act as free-templates and these bubbles creates numerous gas-liquid interface inside the solution
In this current research work, the main motivations are to (i) analyze the phases present during calcination of borohydride derived as-synthesized powders, (ii) retain both amorphous as well as crystalline phase (t) of zirconium oxide up to moderate temperature, (iii) retain porous nature in amorphous as well as crystalline powders up to moderate temperature, (iv) study the nature of porous nanoparticles in terms of pore size, shape and its distribution at different calcination temperature, (v) understand the pore hysteresis of the as-synthesized as well as calcined samples, and (vi) correlate the pore size, pore volume as well as surface area of borohydride derived porous powders with the available literatures to find out the potential of these materials for use in different applications

Summary

Introduction

Porous amorphous zirconium hydroxide/oxide has found to be promising application for removal of toxic ions[17] In this context, different synthesis methods including gelation, precipitation, hydrothermal and sonochemical using the common surfactant-assisted template method were accommodated to prepare porous materials with various shape and size[25,26,27]. In this current research work, the main motivations are to (i) analyze the phases present during calcination of borohydride derived as-synthesized powders, (ii) retain both amorphous as well as crystalline phase (t) of zirconium oxide up to moderate temperature, (iii) retain porous nature in amorphous as well as crystalline powders up to moderate temperature, (iv) study the nature of porous nanoparticles in terms of pore size, shape and its distribution at different calcination temperature, (v) understand the pore hysteresis of the as-synthesized as well as calcined samples, and (vi) correlate the pore size, pore volume as well as surface area of borohydride derived porous powders with the available literatures to find out the potential of these materials for use in different applications

Methods

Results

Conclusion