Richard Lewis

PDRA, Cardiff University
  • Cardiff University
  • United Kingdom

About Richard Lewis

Experienced Postdoctoral Research Associate, Chartered Chemist and Senior Team Leader working within the Cardiff Catalysis Institute, Cardiff University.

Subject

Analytical chemistry Catalysis Green chemistry Materials chemistry Surface chemistry

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Behind the Paper

Recent Comments

Jul 21, 2021
Replying to Richard Lewis

Hi Isatou,

Many thanks for the question. The reactive oxygen species (ROS) are highly energetic and will individually have a lifetime on the order of nanoseconds. The lifetime of any residual H2O2, which has some (limited) anti-microbial properties will last somewhat longer, no longer than a few minutes, depending on environmental conditions (pH / temperature / presence of salts in the water etc ). This is one of the major advantages of this approach compared to chlorination, no toxic chemical residues!

The ROS are generated over the catalyst through reaction between very dilute streams of H2 and O2, rather than being cleaved from the catalyst surface, so as long as both gases are supplied constantly, under ideal conditions, the catalyst will continually generate ROS. 

Hi Isatou, 

Thanks for these comments. 

Theoretically the resources required to generate the ROS should not be prohibitive and would consist of air (to provide O2), water and electricity, with H2 generated from water splitting. This technology really could use water to treat water! The concentration of H2 used by our system is comparable to that generated by any commercially available electrolyser, run from a generator or even renewable sources. 

Your point about changes in water quality and the need for continual monitoring, for example after a storm event or an accidental spill,  is something we have considered and indeed is an area that many water treatment companies are pursuing.  Thankfully there seem to be a number of affordable, remote water quality management systems available commercially.

The use of superoxide in biotherapy is definitely an interesting topic and there is currently a wide field of research investigating the use of superoxide for the safe treatment of tumours. Our catalytic materials can definitely be modified to deliver tumour targeting species in situ, at a desirable rate. 

Best wishes, 

Rich 

Jul 13, 2021

Hi Isatou,

Many thanks for the question. The reactive oxygen species (ROS) are highly energetic and will individually have a lifetime on the order of nanoseconds. The lifetime of any residual H2O2, which has some (limited) anti-microbial properties will last somewhat longer, no longer than a few minutes, depending on environmental conditions (pH / temperature / presence of salts in the water etc ). This is one of the major advantages of this approach compared to chlorination, no toxic chemical residues!

The ROS are generated over the catalyst through reaction between very dilute streams of H2 and O2, rather than being cleaved from the catalyst surface, so as long as both gases are supplied constantly, under ideal conditions, the catalyst will continually generate ROS.