The work presented in this dissertation focuses on two key areas of research, namely i) the use of 4-nitrophenol reduction as a model reaction for benchmarking the performance of metallic nanoparticle catalysts, especially with regards to developing best practices for catalytic benchmarking as well as developing a holistic mechanistic understanding of the reaction and ii) the development of advanced fabrication techniques towards the synthesis of periodic arrays of substrate-immobilized plasmonic gold hexagonal and triangular nanoplates. The first portion of this document briefly details the field of nanomaterials in general and how these types of materials are of critical importance to our everyday lives. An introduction and description of catalysis is then presented, and the necessary background information required to fully understand the catalytic benchmarking of nanoparticles utilizing 4-nitrophenol reduction is discussed. Practical experimental methods for determining catalytic performance in the lab are also detailed, as well as new recommendations for testing procedures and best practices that were developed from our discoveries and research. The significant contributions made to the field of catalysis are then presented where the main contributions discussed are 1. The significant impact of sodium borohydride on the 4-nitrophenol reaction with regards to catalyst dosage and induction time, 2. The critical role of sodium borohydride as not just a reducing agent but as a promoter of ligand desorption during the 4-nitrophenol reaction and recommended best practices for catalytic testing, and 3. The capability to utilize 4-nitrophenol reduction as a facile test for determining metallic catalyst leaching. Additionally, a second focus of my research is then discussed, namely work carried out in the field of nanomaterials fabrication, specifically with regards to fabricating arrays of epitaxially aligned substrate-immobilized plasmonic nanoplates. A brief background for nanoplate synthesis on substrates is described, where special attention is given to motivating the importance and applications of this category of materials. The significant contributions I have made to the field of nanoplate fabrication are then presented where the main contributions are 1. The fabrication of large area arrays of epitaxially aligned substrate-immobilized hexagonal gold nanoplates utilizing Brij-700 surfactant and 2. The fabrication of triangular nanoplates with a high degree of edge sharpness utilizing Brij-700 coupled with hexadecyl trimethyl ammonium bromide (CTAB) surfactant that show polarization-dependent refractive index sensitivity response. Lastly, a summary of our research findings and important contributions to these fields is presented.