Micron-Scale\nVertical MoS<sub>2</sub>/Porous g‑C<sub>3</sub>N<sub>4</sub> Piezocatalyst via a Precursor’s Supramolecular\nSelf-Template Architecture: Degradation and Hydrogen Evolution

Piezocatalysis can effectively harvest\nvarious kinds of mechanical\nenergy with high entropy from the environment and drive some redox\nreactions without light irradiation, where MoS<sub>2</sub>- and g-C<sub>3</sub>N<sub>4</sub>-based piezocatalysts are recent research hotspots.\nThis study constructs an architecture of ordered melamine hydrochloride-cyanuric\nacid/MoO<sub>4</sub><sup>2–</sup> supramolecular precursor\nvia self-assembly, serving as a self-template for in situ tight growth\nof vertically aligned micron-scale MoS<sub>2</sub> on porous foam-like\ng-C<sub>3</sub>N<sub>4</sub>(CM<i>x</i>) under S vapor with\na bioinspired rooting and sprouting-like process. Experiments, DFT\ncalculations, and finite element simulations collectively confirm\nthe high piezoresponse of the CM<i>x</i> with high exposure\nof active sites and enhanced mechanical energy collection. The vertical\ninterfaces and built-in electric fields in the composite induce efficient\ncharge carrier separation and transfer. The optimized CM0.77 efficiently\ndegrades various organic dyes and antibiotic under dark ultrasound\n[rhodamine B (RhB): 0.47 s<sup>–1</sup>, methyl orange (MO):\n0.05 s<sup>–1</sup>, methylene blue (MB): 0.21 s<sup>–1</sup>, and tetracycline hydrochloride (TC): 0.03 s<sup>–1</sup>] and achieves hydrogen evolution (2431 μmol·g<sup>–1</sup>·h<sup>–1</sup>). Under simulated water flow (10 L/min),\nthe expanded CM0.77/Al<sub>2</sub>O<sub>3</sub> porous foam ceramic\n(CM/alumina ceramic) purifier device degrades 95% of 400 mL of RhB\nwithin 25 min. The developed ordered vertical MoS<sub>2</sub>/g-C<sub>3</sub>N<sub>4</sub> piezocatalyst demonstrates rapid pollutant degradation\nand efficient hydrogen evolution under water flow and ultrasound,\nproviding new insights for constructing multidimensional piezoelectric\ncomposites for environmental remediation and clean energy production.