"Teacher, please help me."
As a Chinese native speaker, both 帮 and 帮助 can be used as a verb, the nuance is that 帮 is more informal and colloquial, while 帮助 is more formal. Either 帮 or 帮助 is seldom used as a noun.
Furthermore, there is another match, though not perfectly, in Chinese and English: 请帮我一个忙。 <-> Please give me a hand. Here 忙 can be grammatically understood as a noun, but that cannot be translated directly, like "hand" in "give me a hand".