Zeng, was found unconscious in his house by police on yesterday and taken to hospital where he died.
Prior to his suicide, he had posted dozens of microblogs, expressing depression and loneliness.
"I decided to leave the world after deep consideration, don't persuade me to live. I just hope it won't be too painful," the post said.
He used hypnotic drugs, tapes and coal for suicide then took the drugs and burned the coal.
"I cannot save myself any more as the drugs took effect and I lost strength completely..."wrote his last microblog.
"He told me that he fell in love with a girl online, but he was not sure whether she loved him," Zeng's grandmother said, "His parents were divorced when he was 2 years old and he lived with his mother. However, some years later, his mother remarried. So he has since lived with me."
"I love you, but I'm sorry, I will disappear quickly," Zeng wrote before his death.
During the process, many tried to persuade Zeng not to do it, but to no avail. Others criticized him as an attention seeker.
Several similar cases have occurred in China.
"The government should take timely measures to reduce such tragedies. Schools and communities should also provide psychological consulting to help prevent suicide attempts," he said.