Hi,
so you want to say that Chinese as noun doesn't exist?
what about "The Chinese" - when refered to as a nation? Yes, but as noted, this refers to the people while China refers to the whole country (eg the land, the people, everything).
You can also 'He's a Chinese", referring to one person. My Chinese students often say this. However, in my experience, Western people rarely or never use this noun expression. We say things like 'a Chinese person'.
best wishes, Clive