School of Chemistry & Physics

Prof Werner van Zyl

Professor


Werner van Zyl earned his BSc (Chemistry and Geology) and BScHons degrees (Chemistry) as well as a MSc degree (1992) in synthetic organometallic chemistry working on gold and platinum carbene complexes at the former Rand Afrikaans University (RAU) (now University of Johannesburg). Following a 2.5 year stint in the chemical industry (1992-1994) working at Implats as a Development Chemist, he pursued a PhD degree in (Inorganic) Chemistry at Texas A&M University, USA, under the supervision of John P. Fackler, Jr. (Distinguished Professor Emeritus, retired). The Fackler group worked within the auspices of the Laboratory for Molecular Structure and Bonding under the direction of the late F. Albert Cotton. Indeed, both F.A. Cotton and Nobel Prize laureate G. Wilkinson (1973) are part of his academic genealogy. 
 
Following his PhD, he was appointed a NWO Postdoctoral Associate (1999-2003) in the Inorganic Materials Science Group, University of Twente, Enschede, The Netherlands. After his postdoctoral stay, he was directly appointed at Senior Lecturer level in the Department of Chemistry at the University of Johannesburg (UJ) in September 2003. 
 
In May 2008, van Zyl relocated from UJ to the UKZN where he is currently Full Professor. He has graduated 11 PhD students and 14 MSc students to date. He currently supervises 8 PhD and 2 MSc students and mentors 2 postdocs.

Research interests

Over more than 20 years, his research interests cover a broad area within molecular and materials chemistry, with a strong focus on:

  1. sulfur-based ligands and ligand design, especially the dithiophosphonates and dithiocarbamates,
  2. the chemistry of the Group 11 metals (Cu, Ag, Au),
  3. formation of metal clusters and hydrido clusters of Cu, Ag and Au,
  4. study of solid-state luminescence of Group 11 metal complexes and materials. 

Since 2017, there has also been a shift in research focus in the following three areas:

  1. Biomass conversion and fabrication, especially of cellulose, new nanocellulose fabrication, lignin and sugarcane products, and use in SERS, luminescent paper, and catalysts.
  2. Energy, focusing on transparant and flexible solar cells and hydrogen and CO2 generation, capture, storage and use.
  3. Water, focusing on desalination, esp. capacitive deionisation and redox active electrodes, and reverse osmosis processes. 

Research profiles

Research overview

  • Inorganic chemistry of Group 11 metals: Cu, Ag, Au
  • Ligands with dichalcogen donor atoms (esp. dithiophosphonates). Orthogonal ligands
  • Solid state luminescence of closed-shell d10 systems
  • Metal cluster and metal hydride cluster chemistry of Cu, Ag and Au
  • Biomimetic nanomaterials chemistry; Nanocomposite chemistry
  • Biomass: New materials, nanocellulose, lignin chemistry, SERS
  • Water: Desalination, solar-driven interface evaporation, capacitive deionization
  • Energy: H2 storage, and CO2 reduction (photo)catalysts

Collaborators

  • Prof CW Liu, Dept of Chemistry, National Dong Hwa University, Hualien, Taiwan.
  • Prof N Revaprasadu, University of Zululand
  • Prof SB Jonnalagadda, School of Chemistry and Physics, UKZN.

Current projects

 

Project 1: Group 11 metal complexes with orthogonal ligand scaffolds: Group 11 metals (Cu, Ag, Au) has the ability to form metallophilic interactions and thus pursued to develop multifunctional materials. Heteronuclear complexes of the coinage metals (Cu, Ag, Au) are promising candidates to tune electronic and optical properties which are not readily accessed by their homometallic congeners. We study orthogonal ligands which are rationally designed to access heteronuclear coinage metal complexes and studied in terms of their unique properties. The aim is to prepare bifunctional ligands that contain both soft and hard donor atoms on the same ligand unit (orthogonal ligands) as they have the potential of providing different coordination modes to selectively synthesise heterometallic complexes in a predictable manner, we focus specifically on sulfur (soft) and nitrogen/oxygen (hard) donor atom sets. The S/N and S/O orthogonal ligand combination to form heterometallic complexes is very rare. Once the synthesis, characterization, and structural analysis are complete, the compound are subjected to a suite of investigations with regard to its optical, catalytic, and biological properties, and is complemented with theoretical investigations.

 

Project 2: Cellulose is regarded as the most abundant biopolymer and renewable material on earth and is known for its biodegradability, non-toxicity, and biocompatibility. We formed nanocrystalline cellulose (NCC) from synthetic materials isolated from cigarette filters as well as natural materials isolated from melon seed shell. We formed bacterial cellulose and composites from a dialysis-free Kombucha-based process. The nanocellulose was used to both stabilise and reduce silver(I) to form silver nanoparticles (AgNPs); the composite NCC/AgNPs was investigated as a sensor in the detection of toxins using surface-enhanced Raman scattering (SERS). We additionally demonstrated for the first time the preparation of luminescent cellulose paper through the embedding of a tetranuclear Cu(I) cluster by performing a chemical reaction directly on Schweizer’s reagent used as the inorganic solvent. Finally, we used NCC as a component in a wearable strain sensor based on electroconductive hydrogel composites for human motion detection.

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