Comment on "CO 2 as oxidant: an unusual light-assisted catalyst free oxidation of aldehydes to acids under mild conditions" by S. R. Khan, S. Saini, K. Naresh, A. Kumari, V. Aniya, P. K. Khatri, A. Ray and S. L. Jain, Chem. Commun ., 2022, 58 , 2208.