Yes, plastic water bottles can potentially explode if you place them in the freezer. This is due to the fact that water expands when it freezes, and if there isn't enough space for the water to expand within the bottle, the pressure can build up to the point where the bottle ruptures or bursts.
When water freezes, it expands by approximately 9% in volume. In a plastic water bottle with a sealed cap, there is limited space for the ice to expand. As a result, the pressure inside the bottle increases as the water freezes, and this can cause the bottle to crack or explode.
To avoid this risk, it is advisable not to freeze plastic water bottles with a sealed cap. If you want to chill water in the freezer, leave some room for expansion, or consider using containers specifically designed for freezing liquids safely, such as freezer-safe glass or plastic containers with ample headspace. Additionally, consider using reusable water bottles made from materials designed to withstand freezing temperatures without the risk of bursting, such as high-quality BPA-free plastic or stainless steel.