  We explore the photocatalytic ability of honeycomb lattice of
borocarbonitride, $BC_{6}N$, investigating its opto-electronic properties and
band-edge alignment based on hybrid density functional theory. We observe that
along with pronounced visible absorbance, $BC_{6}N$ exhibits a good reducing
ability. It is capable of depositing heavy metal ions, hydrogen fuel generation
and carbon dioxide sequestration through photoelectrocatalysis. To broaden its
applicability we further tune its redox ability using biaxial strain. We
observe even a slight expansion makes this material capable of performing
simultaneous oxidation and reduction, which is essential for waste management
and hydrogen generation through spontaneous water splitting. In this study, we
propose $BC_{6}N$ to be a promising potential candidate as metal free 2D
photocatalyst and show ways to tune its applicability to address multiple
environmental crises.
