L-CoS was prepared through a self-templating approach using ZIF-67 precursors as template (see Experimental Methods). The PXRD pattern (Figure ) of the as-prepared L-CoS matches well with the standard jaipurite-type phase (CoS, PDF no. 75-0605), while the observed weakened diffraction signals demonstrate the low crystallinity of L-CoS. From field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM), representative nanobox architectures of L-CoS are evident (Figure and Figure ), preserving the cubic structure of the ZIF-67 precursors. HRTEM images (Figure and Figure ) show interplanar spacings of 2.91, 2.54, and 1.94 Å, corresponding to the main exposed crystal planes (111), (211), and (301) of L-CoS, respectively. This agrees with the observed characteristic diffraction rings in the selected area electron diffraction (SAED) pattern (Figure ). Energy dispersive X-ray spectroscopy (EDX) element mappings and line scan profiles (Figure and Figures ) reveal that Co, S, and O are homogeneously dispersed throughout the nanobox. Correspondingly, the atomic ratio of Co/S was calculated as 1.03 from EDX results (Figure ), which is close to the stoichiometric ratio of CoS. The slight decrease in S content is can be attributed to S deficiencies in L-CoS. This will be discussed in detail in the following section on ex situ XAS characterizations.