Gert Biesta may well be regarded as an activist scholar. The introduction and then the whole paper, for Notebook #3, is well worth a read.
Biesta, G. (2013). Interrupting the politics of learning. Power and Education, 5(1), 4-15. Retrieved from https://publications.uni.lu/bitstream/10993/7833/1/6%20PUB%20Biesta_POWER_5_1_web.pdf
There are many different ways to think about activism and academic work. This short piece by Don Mitchell captures much of the debates. He uses an interesting ploy in the short introduction.
Mitchell, D. (2008). Confessions of a Desk‐Bound Radical. Antipode, 40(3), 448-454. doi:10.1111/j.1467-8330.2008.00613.x Available via library or other sites.
If the theme of activism is of particular interest, there are useful papers that cite Mitchell's essay1.
