His girlfriend also paid tribute to him with a message left on the social networking site Facebook, writing that she was "honoured" to have known and loved him.
Pte Hayes was a rifleman with 6 Platoon, C (Essex) Company.
His senior officers said Pte Hayes had made a "real difference" despite having been in the Army for only a year.
His commanding officer, Lt Col James Woodham, said Pte Hayes had been a "trusted member of the team" whose "energy for life was contagious" and who would be remembered for his bravery and sense of humour.
He said: "He died whilst on patrol in an area that has seen some of the most intense fighting with the insurgents that seek to undermine the Afghan government.
"In the past two months, he and his platoon have given their all to deliver a secure environment for the people of Nad-e-Ali in what are some of the most demanding of conditions."
Maj Christopher Davies, the commanding officer for C (Essex) Company, said Pte Hayes was a "genuinely decent man" who "sacrificed his life doing something he truly believed in".
His friend Pte Daniel Greenland also paid tribute and said he had "never met someone as motivated and brave" and that Pte Hayes would never be forgotten.
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