• Unique imitating growth feature for PdS2 on different 2D substrates enables construction of 2D/2D heterostructures via interface engineering.
• Thin and small PdS2 nanoplates with active defects are induced by PVEIB, resulting in excellent NOR electroactivity with outstanding stability and selectivity.
• In situ generation of SO4^2− during preparation or at high NOR potential reduces activation energy, improving nitrate production efficiency.
• Theoretical calculations confirm the crucial role of sulfate in enhancing NOR performance, offering insights for NTMD-based electrocatalyst design.