Quantum confined silicon nanocrystals (Si-ncs) exhibit intriguing properties due to silicon's indirect bandgap and their highly reactive surfaces. In particular the interplay of quantum confinement with surface effects reveals a complex scenario, which can complicate the interpretation of Si-nc properties and prediction of their corresponding behaviour. At the same time, the complexity and interplay of the different mechanisms in Si-ncs offer great opportunities with characteristics that may not be achievable with other nano-systems. In this context, a variety of carefully surface-engineered Si-ncs are highly desirable both for improving our understanding of Si-nc photo-physics and for their successful integration in application devices. Here we firstly highlight a selection of theoretical efforts and experimental surface engineering approaches and secondly we focus on recent surface engineering results that have utilized novel plasma-liquid interactions.