A platform material composed of 2D gold (Au) nanodot plasmonic single-lattices (Au-nD-PSLs) featuring tailor-engineered geometric features for visible-NIR light-driven enhanced photocatalysis is presented. Au-nD-PSLs efficiently harness incident visible-NIR electromagnetic waves to accelerate photo-chemical reactions by localized surface plasmon resonance (LSPR) effects. Au-nD-PSLs are fabricated by a straightforward, industrially scalable template-assisted approach, using nanopatterned aluminum substrates as templates. The method overcomes the constraints of direct writing lithography and allows Au-nD-PSLs to be transferred to arbitrary functional flexible substrates. Triangular lattice Au-nD-PSLs feature tunable and controllable characteristic LSPR bands across the visible spectrum. Strongly localized electromagnetic fields around Au-nD-PSLs are responsible for the outstanding photocatalytic performance of these plasmonic nanostructures, as demonstrated by finite-difference time-domain simulations and experimental observations. Our approach of rational engineering of LSPR effects in Au-nD-PSLs provides exciting opportunities to develop high-performing and reusable photocatalysts that harvest the visible-NIR spectrum for a broad range of optoelectronic and plasmonic applications.