Control reactions in the absence of photocatalyst, nickel co-catalyst, or light produced no product, showing that a light-driven dual catalyst reaction is occurring in the absence of bulk solvent. Removal of the milling balls gave a much lower yield of 35%, suggesting the greater importance of more efficient mixing in this more complex system. The yield could be increased to 68±1% in 3 hours using the V2 holder at a 0.3 mmol scale with one 6 mm ball. We then compared the efficiency of the mechanophotocatalysis protocol with the solution-state reaction conducted at 0.1 M concentration in DME under both aerobic and anaerobic conditions. While the anaerobic solution-state reaction gave the product in 77±0% yield in 3 hours, the yield of the solution-state reaction under air was lower (51±4%); further, the yield did not improve over a longer reaction time (47±2% in 24 hours). Thus, under air, the solution-state reaction is less efficient than the mechanophotocatalysis reaction (68±1%). This reduction in yield is a result of the aerobic solution-state reaction conditions producing a significant amount of protodehalogenated byproduct (41±4%), while both the mechanophotocatalysis and anaerobic solution-state reactions produced significantly smaller amounts of this byproduct (20±3 and 22±0%, respectively). We tentatively assign this to be a function of more efficient quenching of the triplet excited state of the photocatalyst by oxygen in solution, encouraging protodehalogenation following oxidative insertion of the nickel catalyst to the aryl bromide. The improved efficiency of the mechanophotocatalysis experiment relative to the solution-state reaction under aerobic conditions is consistent with the results from our previous study. Noting the significant protodehalogenation byproduct, we modified the catalyst loading ratio of the mechanophotocatalysis reaction, giving a final optimised yield of 78±4%, and a reduction in the formation of the protodehalogenated biproduct under aerobic solvent-minimized conditions (9±3%).