The ease of integration coupled with large second-order nonlinear coefficient of atomically thin layered 2D materials presents a unique opportunity to realize second-order nonlinearity in silicon compatible integrated photonic system. However, the phase matching requirement for second-order nonlinear optical processes makes the nanophotonic design difficult. We show that by nano-patterning the 2D material, quasi-phase matching can be achieved. Such patterning based phase-matching could potentially compensate for inevitable fabrication errors and significantly simplify the design process of the nonlinear nano-photonic devices.