As you may have noticed, the papers in the examples mentioned above introduced the subfield by mentioning 1) remission of some types cancer following accidental infection by Streptococcus pyogenes, 2) organic matter in soil as a source of nutrients for plants and of energy for microorganisms, and 3) imaging techniques to visualize the 3-dimensional structure of the materials and components of batteries on nanoscale.
It’s unwarranted that writers begin drafting introductions minus having a good topic.
Quick ways to solve this problem is to browse the internet, do a quick search and come up with a good one that feeds your interests.
Another way to emphasize the importance of the research topic is to highlight the possible benefits from solving the problem or from finding an answer to the question: possible savings, greater production, longer-lasting devices, and so on. For example, instead of saying that X dollars are lost because of malaria every year, say that X dollars can be saved annually if malaria is prevented, or X millions litres of water can be saved by dispensing with irrigation, or X person-hours can be saved in the form of avoided illnesses because of improved air quality or reduced pollution.
As mentioned earlier, a formal review of literature is out of place in the Introduction section of a research paper; however, it is appropriate to indicate any earlier relevant research and clarify how your research differs from those attempts.