Been looking at getting one. Here is what I know so far
https://www.ikea.com/gb/en/p/vindstyrka-air-quality-sensor-smart-40498234 – Ikea – £35, monitors pm 2.5, temperature, humidity, tvocs
9 in 1 WiFi Air Quality Monitor PM2.5, PM10, HCHO, Organic Pollutants, CO, CO2 Multifunctional Monitor – £36, need to find out if it can publish its data