Progress in photocatalysis over the last two decades has been extensive, allowing it to emerge as a commonly employed tool in organic synthesis. A plethora of reactions have been developed that proceed photocatalytically, from the photocatalytic splitting of water to the C(sp 3 )-functionalization of substrates. Despite the wide array of transformations that can be conducted using photocatalysis, due to the heterogeneity of photoreactor setups coupled with the paucity of direct experimental evidence to support the putative photocatalytic mechanism advanced in many reports, it can become difficult to replicate the reported outcomes of photoreactions.