2 sentences

1. 他感到内心一片虚无。

   tā gǎn​dào nèi​xīn yī piàn xū​wú.

   He felt a sense of nothingness inside.

   Source: Dong Chinese Dictionary

2. 他意识到自己追求的名利不过是一场虚无的梦幻。

   tā yì​shí dào zì​jǐ zhuī​qiú de míng​lì bù​guò shì yī cháng xū​wú de mèng​huàn.

   He realized that the fame and fortune he sought were nothing but a hollow fantasy.

   Source: Dong Chinese Dictionary