Emergence of enhanced photocatalytic response in GO-hBN nanocomposites with tuned non-linear optical and surface electronic properties

Abstract

The hexagonal Boron Nitride (hBN) nanostructures with tuned physicochemical properties find huge applications in optoelectronic devices. Herein, we have synthesized nanocomposite of hBN with graphene oxide (GO) in various ratios to acquire composition-dependent variation in their structural, surface electronic, linear, and non-linear optical properties. The insertion of GO in hBN nanosheets has modified their strain landscape, the electronic charge transfers from GO to hBN, increased the working time of free charge carriers, and suppressed electron-hole recombination, thus modifying its work function (WF). GO-hBN nanocomposites observed to have reduced bandgap where creation of defect induced mid-gap states lead to enhancement in non-linear absorption of two photons. Herein, we have established a linear relationship between Urbach energy (E_u), a measure of disorders and non-linear absorption coefficient (α_NL). Additionally, we have observed that the tuned bandgap of the nanocomposites has significantly enhanced their performance as high-performance photocatalysts for the degradation of methyl orange, compared to bare hBN or GO. As a result, we discovered that E_u, α_NL, WF and photodegradation activity of GO-hBN nanocomposites exhibit analogous variations in response to changes in the content of GO. Thus, by strategically prioritizing the modification of a single parameter while considering the potential effects on other relevant properties for application purpose, GO-hBN can effectively harness large spectrum areas for catalytic and optoelectronic applications.