  We show that the rough particles studded with platinum nanoparticles can be
fabricated straightforwardly and in a single step at room temperature. These
rough particles displayed a good catalytic power (100% removal efficiency)
against a model industrial dye (methylene blue) and pharmaceutical residue
(tetracycline) within a reasonable time scale. Further, we illustrate the
effects of particle size, concentration, and contact patterns on the
performance of rough catalytic particles. The semi-batch conditions favoured
the complete decomposition of tetracycline within 40 min, but the batch-wise
operation offered a good contacting pattern for methylene blue yielding a
maximal output within 10 min. The kinetics of the heterogeneous catalytic
process modelled by Langmuir-Hinshelwood kinetics predicts that the given
methylene blue decomposition reaction induced by the rough particles follows
the pseudo-first-order kinetics. The rate constants for the reaction catalyzed
by 0.6 and 1.0um-sized rough particles are 0.048 and 0.032 min^-1,
respectively. Furthermore, we established the proof-of-concept using
magnetically-responsive rough particles for real-time applications, including
decontamination and recovery of catalyst particles via an externally applied
magnetic field in one cycle. Our proposed method helps achieve a near-100%
degrading efficiency within 10 to 40 min at minimal catalytic particle
concentration, i.e., 200 ppm. Since we can turn the rough particles into
super-paramagnetic, we can recover and reuse them for several wastewater
treatment cycles without incurring any running costs.
