However, in the presence of aryl iodide (i.e. 4iodobenzotrifluoride, 4-IBzCF3) the lifetime of the BET decay is shortened significantly (Fig. ), indicating a faster recovery of Ir(III). This initially surprising result can be explained through a hypothesis in which Ir(IV) oxidizes OA-generated iodide to produce an iodine radical and recover Ir(III). By variation of the aryl iodide concentration in a Stern-Volmer approach, a rate constant is obtained for the reaction with 4-IBzCF3 of 4.7 * 10 4 M -1 s -1 , in agreement with previously measured rate constants for oxidative addition with similar aryl iodides at related Ni(I)-bipyridine type complexes (Fig. ). In order to explain why the observed kinetics conform to the Stern-Volmer equation, justifying the plot in Fig. , we hypothesize a unimolecular BET event in competition with bimolecular oxidative addition, followed by a fast (> 6.0 * 10 5 s -1 , see Supporting Information) unimolecular oxidation of OAgenerated iodide by Ir(IV) (See scheme in Fig. ). Ir(IV) is thermodynamically capable of oxidizing iodide based on cyclic voltammetry experiments (See SI, Table ), and we observe byproducts of iodide oxidation in TA experiments in the presence of added NaI (See SI, Fig. ). In sum, our observations are consistent with the hypothesis that OA can be followed indirectly through monitoring the Ir(IV) to Ir(III) turnover kinetics. Furthermore, this observation implicates halide oxidation as a relevant mechanistic step in dual Ni/photoredox catalysis.