Symmetry-breaking structure of Mg modified ZnIn2S4 microspheres towards photocatalytic hydrogen peroxide production

The symmetry-breaking structure can induce lattice distortion, modulate electron distribution, suppress carrier recombination, and optimizing catalytic activation via asymmetric atom interactions, which is of vital importance for improving the photocatalytic H 2 O 2 production activity. In this paper, the symmetry-breaking structures of Mg-modified ZnIn 2 S 4 microspheres are synthesized through a convenient‌ single-step hydrothermal method using the gradient introduction amounts of Mg. X-ray absorption spectrum, X-ray photoelectron spectroscopy, and transmission electron microscopy indicate that the introduction of Mg can modify the bond lengths and crystal plane angles of the substrate material to construct a symmetry-breaking structure. The photocatalytic H 2 O 2 production performance of MZIS-15 is approximately 3.3-fold than ZnIn 2 S 4 up to 2797.0 μmol h⁻ 1 g⁻ 1 . Furthermore, femtosecond transient absorption spectra, photoelectrochemical measurements, and density functional theory (DFT) calculations reveal that, although the optimal symmetry-breaking structure does not significantly alter the light absorption range and bandgap width, it greatly suppresses the recombination of photogenerated electron–hole pairs, enhances the charge separation efficiency, and lowers the adsorption energy barrier of the O 2 molecule. This work provides a systematic research perspective on symmetry-breaking structures, and also offers new research ideas for the synthesis of advanced catalysts.