He flagged the taxi down on Linden Walk, Toll Bar, at around 12.30am on Wednesday, June 13 before opening the car door and throwing an unknown substance over the driver.
CRIME: Bleeding man asked for help in Sheffield shop after stabbingThe crook then grabbed the taxi driver’s phone before fleeing towards the Manor Estate, Toll Bar.
COURT: Hope Valley drink driver jailed over crash which led to amputation of cyclist's legSouth Yorkshire Police said the 55-year-old taxi driver was unharmed.
The substance hurled at the man is not believed to have been noxious.
An E-fit has been released of the man wanted over the incident.
POLICE: Detectives granted extra time to quiz Sheffield murder suspectA South Yorkshire Police spokesman said: "Officers investigating have carried out enquiries in the area and explored CCTV opportunities and are now asking for your help to identify the man in the E-fit image.
"Do you know who he is?"
Call South Yorkshire Police on 101 and quote incident number 31 of June 13.
Crimestoppers can also be contacted on 0800 555111.