  Reduced graphene oxide becomes one of the most popular materials for
applications in various optical, electronic and sensor devices. Even though
many methods have been already reported for reduced graphene oxide synthesis,
they usually rise issues related to their efficiency, quality and environmental
impact. This work demonstrates a simple, environmentally friendly and effective
method for reducing graphene oxide under ambient conditions using nanosecond
infrared laser irradiation. As a result, a Raman band intensity ratio of
I(G)/I(D) of 4.59 was achieved with an average crystallite size of ~90 nm. This
graphene is of higher quality than what can be achieved with most of the
existing methods. Additionally, the demonstrated reduction technique allows the
selective reduction of graphene oxide and control the amount of functional
groups on the surface of the material. Gas sensors fabricated according to the
proposed technique efficiently detect NO$_2$, NH$_3$, and H$_2$S with the
sensitivity down to 10 ppm.
