The food industry is responsible for generating considerable amounts of waste, such as excess fruits and leftover sugars, which contribute to resource depletion and pose environmental challenges. This research delves into the application of gold-modified graphitic carbon nitride nanosheets (Au/CN) as a potent catalyst for the transformation of these food wastes into H2 via piezoelectric reforming during sonication. Au/CN demonstrated a superior rate of H2 evolution compared to pristine g-C3N4 (i.e., 1533.3 vs. 364.9 µmol/g/h) and it maintained its efficiency through multiple cycles of use. The catalytic activity was found to be optimal at a neutral pH level and with increased sugar concentrations. The enhanced catalytic performance of Au/CN was ascribed to the efficient segregation of charge carriers as well as the reduced charge transfer distance. This study underscores the viability of using Au/CN as a means for converting food wastes into a sustainable source of H2 energy.