Direct capture of solar energy for chemical transformation via photocatalysis proves to be a cost-effective and energy-saving approach to construct organic compounds. With the recent thriving in photosynthesis, photopolymerization has been established as a robust strategy for the production of specialty polymers with complex structures, precise molecular weight, and narrow dispersity. A key challenge in photopolymerization is the scarcity of effective photomediators (photoinitiators, photocatalysts, et.al) that can provide polymerization with high yield and well-defined polymer products. Current efforts on developing photomediators have mainly focused on organic dyes and metal complexes. However, most of the developed PCs consist of metals or organic dyes that often require elaborate synthetic protocols and purification steps to tune the redox potential and electronic properties. Therefore, the development of robust new generation PCs for photoinduced polymerization is of general interest. Nanomaterials (NMs), particularly semiconducting nanomaterials (SNMs) are suitable candidates for photochemical reactions due to their unique optical and electrical properties, such as high absorption coefficients, large charge diffusion lengths and broad absorption spectra. The objective of this thesis is to develop fundamentally new, versatile, externally regulated and controlled photomediated polymerization for the synthesis of insulating polymers and functional polymeric materials using light-triggered semiconducting nanoparticles (SNMs). Specific Aim 1 is to manipulating the ligand shell of semiconducting quantum dots (QDs) to enhance their photocatalytic performance in photopolymerization and provide a structure-relationship guideline for surface chemistry design (Chapter 2). Specific Aim 2 is to fabricate functional polymer-QDs hybrid materials with our well-developed methodologies(Chapter 3 and Chapter 4). Specific Aim 3 is to discover robust nanomaterial photoredox catalysts for near-infrared light-mediated living polymerization (Chapter 5).