|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Materials for Energy Conversion and Storage
||Structure-Reactivity Relationships in Pt-functionalized Graphitic Carbon Nitrides for Solar Hydrogen Production
||Diane Haiber, Peter Crozier
|On-Site Speaker (Planned)
Graphitic carbon nitrides (g-CN’s) are polymeric semiconductors (bandgap=2.7 eV) that can be employed as photocatalysts for solar hydrogen evolution under visible light. Hydrogen evolution rates of g-CN’s are highly sensitive to the degree of polymerization, characterized by residual hydrogen within the structure. Because g-CN’s suffer electron beam damage via radiolysis, direct imaging of their structure on the nanoscale has not yet been achieved.
By combining aberration-corrected electron microscopy and ex-situ photoreactions, we elucidate structure-reactivity relationships in the g-CN/Pt system. The in-plane disorder of three g-CN’s is revealed by employing low-dose TEM imaging. Z-contrast STEM imaging was used to obtain the unique Pt dispersions on each g-CN support. By accounting for Pt dispersion, the intrinsic activity (in terms of turn-over-frequency) associated with each g-CN support is reported. We will discuss the correlations between in-plane disorder and surface active site density to better understand the functionality in the g-CN/Pt system.