The extensive use of antibiotics poses a significant risk to human health, and electrocatalysis has demonstrated effectiveness in treating antibiotic contamination.This study details the synthesis of MnO2/Pd(OAC)2@CA particle electrodes using a straightforward one-step sol-gel method and the development of a three-dimensional electrocatalytic reactor (3DER) to remove antibiotics from water.Under optimal conditions (1.5 g/L MnO2/0.3%Pd(OAC)2, pH 3 and 2.0 V), a degradation of 97.8% of tetracycline hydrochloride (TCH) at a concentration of 15 mg/L is achieved within 80 min.The rate constant in the 3DER (k = 0.0389) is 9.26 times greater than that in a two-dimensional electrocatalytic reactor (2DER) (k = 0.0043).After ten cycles of treatment, the degradation rate of TCH remains at 86.4%.Furthermore, under optimal conditions, the energy consumption of the 3DER is significantly lower than that reported in other studies, with an EEO value of only 0.033 kWh/m3.Radical scavenger experiments and ESR (EPR) studies identify the free radicals involved, including •OH, SO4•-, H*, and •O-2.Theor. calculations and toxicity assessment reveal a general reduction in the toxicity of the intermediate products formed during the electrocatalytic degradation of TCH.In summary, the MnO2/Pd(OAC)2@CA particle electrodes exhibit high electrocatalytic degradation efficiency, excellent recyclability and reusability.The 3DER constructed using particle electrodes demonstrates broad applicability and environmental friendliness, providing a novel solution for remediating antibiotic-contaminated water.